Mother Board And Laptop Repairing Full Course

INDEX

MOTHER BOARD

Chapter 1 :

Introduction of Mother Board ,Component of Mother Board

Chapter 2 :

Components of circuit , ATX power supply , Voltage Regulator circuit of Motherboard .

Chapter 3 :

Structure of mosfet , Method of mosfet testing on motherboard , Numbers and types of inductors used in motherboard , Use of power mosfet on mother board , Specification of mosfet Power supply on motherboard , introduction of power mosfet FAQs , place of VRM circuit of motherboard , Circuits of given signal SB of VRAM circuit on south chipset0 , Methodes of VRAM testing , Testing of cpu supply , Position of testing of v-core voltage , Pentium 4 motherboard , Testing stem of VRAM circuit of V-CORE voltage .

Chapter : 4

General circuit diagram of voltage stability circuit for chipset , Specify of voltage circuit stabilizer for motherboard Chipset , Design Of voltage stabilizer using amplifier IC power mosfet control algorithm , Designing of voltage stabilizer by using two circuit , Voltage IC , Designing of voltage stabilizer by using Ic filters and drivers , Designing of voltage stabilizer by using feedback voltage stabilizer IC , General question and answer about voltage stabilizer circuit .

Chapter 5:

Ram power supply , source voltage stabilizer circuit for video card A GP4x , 8x.

Chapter 6 :

Working of clock generator circuit ,Special features and location of clock generator circuit , Operation principle of clock generator circuit (clock pulse circuit ) , Methods of testing , Repairing and mistake , Clock pulse circuit on MSI MS-6507 , Methods of fault finding and testing of clock pulse circuit .

Chapter 7:

What is reset signal? , Condition of IC operation , Rest signal generator on motherboard , Rest signal generator circuit system of motherboard , Condition of south chipset for system rest signal , Causes of rest signal losses on motherboard , Testing method of system rest signal .

Chapter 8:

Working of CPU , Operation testing of CPU , Steps of removing faults of CPU

Chapter 9:

Super I/O controller department

Chapter 10:

Bios , Testing and fault finding of bios , bios beep code of motherboard , DG31PR , DH55TC , Workstation board wx58bp ,lay out of motherboard , Block diagram , Features , penal and header detail , Beap coad , Error message and post code .

Chapter 11:

Fault finding of motherboard (color page)

CHAPTER -1

MOTHERBOARD

INTRODUCATION:

Motherboard is an electronics device which is a printed circuit board (PCB), used in the laptop and computer. This is also called main board or system board. Besides the computer motherboard also used in robot and many other electronic devices. This device combines the various components and put them at their places and also provides common power supply to all the components. A computer is design by microprocessor, main memory and components of motherboard and also with it , some other device and controls are connected with motherboard for controlling the sound , video display & storage in it .

Chipset is the main part of motherboard. Imagine of specification and capacity of motherboard is performed with the help of chip. There are controller in the motherboard for Centre Processing Unit (CPU) , Memory Storage , Serial Port and Keyboard and Disk Drive . Motherboard which have minimum one socket or one slot and have one or more microprocessor they have high priority. And with addition they have one clock generator, one chipset, and slot for expansion card and power supply connectors.

· The running speed of these device of motherboard is different.

For example: The speed of CPU bus is 800 MHz but speed of RAM bus is 400 MHz and bus speed of sound card is 66MHz.

· Beside of No Bus, Street Circuit is also different. Thus CMA devices are not connected directly with each other.

· Motherboard is such type of device which works at mediator for connection all the device at common linked computer in the similar structure So motherboard performed the following function :

· Operation of Motherboard :

à Mounting the components together at a computer system .

à Controlling the bus elements for marketing the capable of different components.

à Provided a clock pulse for synchronizing all the activity of system

Due to all the important things, because of any fault in it , computer does not work .

In the computer system, made with the components connected on it main component of motherboard are north bridge (north chip) , south bridge (south chip) SiO , IC(IC controller ports ) etc. These three components of he motherboard are introduced in computer in a unified component to perform as mediator for motherboard.

MAIN COMPONENTS MOTHERBOARD :

1. CPU Socket (for plugging the CPU) :

Here many types sockets are used for plugging of CPU according to the category of motherboard :

· For Pentium3 at motherboard socket 370

· For pentium4 at motherboard socket 478

· For Pentium D at motherboard socket 775

· For Intel core i3 , i5 socket 1156

· For Intel core i7 socket 1366

2. North bridge chipset (GMCH)

à North chipset are responsible for controlling the hgh speed components like CPU, RAM, and video card.

à These chipset are controlling the bus speed and they sure that between control switch And components data are continually and smoothly obtaining or not , who are take out the speed of CPU and ram in working mode .

à This types chipset control the request which are going in a definitely duration from each medium like a traffic light , while bus speed is control of direction of intersection in constant speed for many wheecls.

3. South bridge chipset (ICH Input /Output Controller Hub):

The working of south chip set are same like the north chip set but south chip control the driver components like :- Sound card , Net card , Hard drive , CD-ROM drive , USB ports and BIOS IC and SIO etc .

4 .ROM bios (Read Only Memory – Basic in out System):-

à ROM is read only memory ICs and BIOS is a programs , Which are loaded in ROM by main board manufacture . There are following functions in the BIOS program .

à Starting the computer and maintaining the operation of CPU .

à Checking the Fault of RAM and Video card .

à Managing the Chipset Drivers for North, South Chipset , IC-SiO & ON board Video card .

à Providing the CMOS SETUP default setting for those machines which cannot operate the CMOS Settings.

5. SiO (super input controller):-

à Sio controls the Serial Port like COM Port , PS/2 Poart and Parallel Ports devices like Printers , Scanner , Floppy Controller

à SiO is also superwise the other departments at main activities for providing the signals .

à Integrated Power Switch Control Circuit , Rest Signal Generate system

6. Clock Generator (Clocking)- Clock Circuit Pulse :

à Clock pulse play important role at motherboard. They synchronize all the operations of computer at a same time. If this is break then clock circuit components cannot be work properly at the motherboard .After the first operation, these are the main sources of clocking circuit supply.

7. VRAM (Voltage Regulator Module ):

This is power supply control circuit control for CPU v- core, which is design from 12v/2A circuit voltage . This is also adjusting the voltage and current level of CPU. This circuit includes the followings components like MOSFET , PWM IC , Phase Driver IC , dr MOSFET Flter circuit L,C etc

8. AGP or PCI express slot:

AGP or PCI access slot, which is control by north chip set.

9. RAM SLOT:

To add the RAM , RAM slot are used at motherboard . Ram slot are control by north chip set. Memory is essential part in a computer system.

10. PCI:

To add like card, sound card, card in PCI extension are controlled by south chip set.

11. IDE PORT :

For adding gateway chipset , IDE port drive like HDD , CD_ROM and DVD are performed by using south chip set .

12.SATA PORT (serial advance technology attachment ) :

SATA is a technique which is adds the hard disk from computer . It is replacement of PATA .Before coming SATA, PATA was also called the IDE or ATA. SATA uses the thin cable for connecting the hard disk from computer, which are mounted at SATA port at motherboard. Now days SATA are mainly used in maximum computer.

13. USB PORT (universal serial bus) :

The main function of this device is exchange of data from each other in a serial manner with high with high speed from USB devices. USB are two types but physically one types. In USB 1.0 data transfer speed is 1.5mbps .data transfer speed of USB 1.1 versions is maximum 12 mbps and data transfer speed in USB 2.0 versions is 480 mbps .

14. AUDIO DRIVER CHIP:

The main function of audio port devices is converting digital signal into analog signal and providing audio signal at audio port . These audio driver chips are used in different from . Audio driver port are available in different from and watt like 1.1,2.1,3.1……………7.1 audio channel.

CHAPTER 2

POWER SOURCE CONTROLLER OF MOTHER BOARD

1. Components of Circuit :

Main functions of the Sources at Motherboard Controller are the power switch , providing voltage stability for CPU , Chipset, RAM , Video Cards and other components .

Those subject which are needed to understand by us , they are following :

à Voltage of ATX power supply

à Circuit stable voltage power supplies for CPU VRAM .

à Matching of steedy power supply voltage for chipset.

à Stable voltage circuit for RAM.

2. ATX Power Voltage :

There are two parts in ATX power supply –standby and main sources (main power).

à When it is connect in 220V AC power sources than standby work immediately and provides to south chip set and Sio IC .(the main source does not work until the power switched is not pressed the i.e. power source does not obtained)

When you pressed switch =>effect on start up circuit in the south chip set =>ON.P is obtained from given chipset . When On power command is received to SiO then ON power is given to green wire power connector for continue making on power, when P.ON = (=0V) =. Main source main power will work.

à Function of main source => Increasing the Motherboard supply voltage , given 3.3V by orange wire 5v by red wire , 12vby yellow wire , -5v by white wire and -12v by blue wire.

· Black wire : Common (Ground )

· Red wire :5.0 v

· Purple wire 5v STB (first level)

· Blue wire :-12v

· Orange wire :3.3v

· Yellow wire 12v

· White card :-5v

· Green wire : P.O.N.(Open source command)

· Grey wire is PG (power good)

Similar Voltage are received from similar color wires of all ATX power supply.

3.VOLTAGE REGULATOR CIRCUIT OF MOTHERBOARD

à Direct voltage supply of componrnts without voltage regulator :

Some components of motherboard are obtained direct power supply without voltage regulator through ATX power supply . These components are:

· Clock generator IC (Clock Pulse) received supply from direct source of 3.3V.

· Direct voltage of 3.3 v, 5v and 5v STB are given to south chop set.

· 3.3v and 5v STB power supply is given to Sio IC from direct sources. Supply is received to all these parts directly from ATX power supply and when we are used lower quality ATX power supply then direct source supply component , given to the motherboard can be damaged .

· Circuit voltage :

Some components like CPU , RAM , video cards , and chipset generally works at low voltage so generally , extra supplies of low voltage 1.3V to 2.5V are given , downing the power levels from Source voltage 3.3V, 5V or 12V

· VRAM (Voltage Regulator Module ) circuit :

· VRAM is regulator circuit for CPU resources. There are functions in this circuit for changing the voltage from 12V to 1.5V. For providing power supply to CPU electronics current is increased according to CPU.

· VRAM circuit down the voltage from 12V to 1.7V at motherboard which are given to the given to the CPU .

· Chipset regulator circuit :

· This is voltage regulator circuit for chipset. Intel north and south chipset are generally uses of 1.5v and VIA chipset uses generally 3V of voltage range.

· RAM Regulator circuit :

· In Pentium 3 system SDRAM 3.3V are used , which are not needed of voltage regulator .

· DDR RAM uses 2.5v voltage , DDR2 RAM uses 1.8v voltage and DDR3 RAM uses 1.5v voltage . So obtaining proper voltage for these & for decreasing the voltage, we are needed the voltage regulator circuit .

à Circuit Description of power supply of motherboard :

· When the plug is in then reaction are start at power sources and motherboard obtained STANDBY => 5V power supply from purple wire.

· When you press the switch and controlling the sources all the circuit are in working mode like P.O.N = 0v for boot , 3.3v, 5v and 12v and a secondary sources of motherboard providing -5v and -12v and for operating main sources .

· 3.3v power supply directly given to the clock generator IC , south chipset , Bios and Sio IC And less power supply from this are provided through regulator circuit to 1.5v chipset (Intel) 3v or chipset VIA .

· Obtain 1.5 v supply voltage source from 12v through VRAM circuit , given to the CPU .

· Given power supply of 5v for chipset and PCI extension card are feed for RAM power through supply voltage regulator circuit.

à Description of process control circuit :

· When the plug is in then the voltage supply is obtained to STANDBY operation , south bridge and SIO IC before the circuit for the 5V STB .

· When you press the switch from south chipset then open sources P.ON command is obtained.

This command is given to IC. And after this controlling the main source main power activities and for power supply at motherboard P.ON is given from Sio IC .

· Operating voltage output of main sources are following :

3.3v supply directly feed to south chip set and accept for PCI extension.

For down the voltage for 1.5v power supply 12v supply is given to the VRAM voltage regulator circuit for CPU .

· If this is operate properly then this is send the VRAM _GD signal to the south chip set that V-CORE is correctly obtaining to CPU . This is signal protection circuit . When this signal is chip set CPU understand the this signal into from of ready chip set activities and provide the rest signal .

CHAPTER -3

DETAIL OF MOTHERBOARD MOSFET

Generally we see the MOSFET on the motherboard, which is used very much. They are used in power supply control circuit for CPU, RAM and chipset .

STRUCTURE OF MOSFET :

MOSFET (metal oxide semiconductor field effect transistor)

MOSFET are two types and have three pins which are as follow:

· Base pin (drain)-D

· Source pin (source) –S

· Gate pin –(gate)-g

Top View of Mosfet

à Identification of N-Channel , P-Channel MOSFET Digital Multimeter :

· First of all , put the multimeter in 2k or diode range .

· Putting the red Probe at Drain & Black Probe at Source , multimeter is showing 240 Ω to 960 Ω resistance then this MOSFET is P-Channel MOSFET

· Putting the Black Probe at Drain , Red Probe at Source ,Multimeter is showing 240 Ω to 960 Ω resistance then this MOSFET is N-Channel MOSFET .

à .Testing of MOSFET

· If GATE to Drain ,GATE to Source ,multimeter is not showing continuity then this MOSFET is OK and if continuity is showing then this MOSFET is short .

· If the multimeter is showing the continuity both side drain to source and source to drain , then MOSFET is short .

· If the multimeter is not showing the continuity both side drain to source and source to drain , than MOSFET is open .

· If the multimeter is showing the continuity in one side drain to source ,source to drain and other side countinuty is not showing then this MOSFET is ok .

NOTE: Before testing of MOSFET , making short the drain , source and gate and discharge them.

Difference between the transistor and mosfets :

MOSFET	TRANSISTOR
1. Gate operating voltage of mosfets is 1.3V.	1.Base operating voltage of transistor is .3v
2.Operating ng temperature of mosfets is -55 to 120 degree Celsius	2.Operating temperature of transistor 0 to 34 degree Celsius .
3.IC made by mosfets is called CMOS.	3.IC made by transistor is called TTL IC.
4.Positive supply of CMOS is called VDD .	4.Positive supply of TTL IC is called VCC.
5. Negative supply of CMOS IC is called VCC.	5. Negative supply of TTL IC is called GND.

à Reverse characteristics MOSFETS (which are used in motherboard) :

· Source pin is insulated from gate pin .

· Gate pin is insulated from drain pin .

· Drain pin from sources pin (when D level is positive) , voltage depend on gate pin .

· When voltage increased from gate to source pin (when drain is positive and source is negative ) then mosfets becomes ON.

· When Gate pin voltage are equal or less than Source voltage then MOSFET becomes off. => In this condition MOSFETS is ok

1. METHOD OF MOSFET TESTING ON MOTHERBOARD :

à Measure the quality control of power MOSFET :

· For testing of quality control you have to need to remove the gate (G) and source (S) pin from circuit then we test the following :

Condition of Broken MOSFET are following :

· Measure between G&S ,then will be lower resistance =>power detectors or shorts -GS

· Measure between G&D there will be low impedance => power detectors or shorts –GD

· After loading the positive for G (for power)which reverse power is checked , they not lead =>

PW TYPE

TYPES AND NUMBERS OF CHOWK COIL (INDUCTOR)USED IN MOTHERBOARD –

PW021-MS**	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
R50	0.5	85 100	1.50	2.40
1R0	1.0	120 150	1.20	1.80
2R2	2.2	300 350	0.85	1.20
3R3	3.3	430 500	0.75	0.98
4R7	4.7	600 700	0.65	0.80
6R8	6.8	780 900	0.55	0.73
100	10.0	1200 1400	0.45	0.61

P W25201B TMS*	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
R47	0.47	47 56	2.20	3.70
1R0	1.0	73 88	1.80	2.70
1R5	1.5	105 126	1.50	2.10
2R2	2.2	129 155	1.30	1.70
3R3	3.3	227 272	1.00	1.30
4R7	4.7	338 406	0.80	1.15

PCMC042T_***MN

L0(µH)

inductance

PCMC (B) type

Rdc(mΩ)

Typical MAX

Ratedcurrent

(A)

Saturationcurrent

(A)

R10

0.10

4.5 5.0

R22

0.22

7.3 8.0

R47

0.47

14.0 15.5

11.5

1R0

1.00

32.0 36.0

3.8

8.5

PCMB042T_***MS	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
R10	0.10	3.5 4.0	12	22
R22	0.22	6.0 6.6	9	13
R47	0.47	12.5 12.0	7	9.5
1R0	1.00	24.0 27.0	4.5	7.0
1R5	1.50	38.0 46.0	4.0	6.0
2R2	2.20	58.0 58.0	3.0	5.0

PCMC053T-***MN	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
R68	0.68	11.0 12.0	8.5	14.0
1R0	1.0	13.0 14.0	7.0	11.0
1R2	1.2	15.0 16.0	6.5	11.0
1R5	1.5	18.0 20.0	6.0	10.0
2R2	2.2	29.0 35.0	5.5	9.0
3R3	3.3	32.0 38.0	5.0	7.0

PS031T-***MS	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
2R2	2.2	75 90	1.40	1.10
4R7	4.7	120 140	1.20	0.77
6R8	6.8	160 190	1.00	0.67
100	10.0	260 340	0.90	0.54

PS031T_***MS	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
2R2	2.2	90 105	1.30	1.10
3R3	3.3	130 150	1.20	0.90
4R7	4.7	170 200	1.00	0.75
6R8	6.8	200 230	0.90	0.65
100	10.0	300 340	0.80	0.52

PS014B_***MS	L0(µH) inductance	Rdc(mΩ) Typical MAX	Ratedcurrent (A)	Saturationcurrent (A)
2R2	2.2	80 95	1.30	1.70
3R3	3.3	100 120	1.10	1.40
4R7	4.7	120 145	1.00	1.15
6R8	6.8	180 216	0.84	1.00

NOTE : when we check the quality of power MOSFET for correction result then for this remove the G&S pins from the printed circuit .

3.USE OF POWER MOSFET ON MOTHERBOARD :-

1. In the voltage Regulator Circuit MOSFET is used for amplified the electronic current .

2. Function of MOSFET in RAM voltage circuit is amplified the electronic . IC LMV algorithm Control the gate of MOSFET by amplifies voltage control . From which voltage regulator circuit provide a constant current and this circuit is provide the effective voltage .

MOSFET is connected to voltage through the coil . DC pulse from is changed into pulse width input voltage is converted into output as we wise and we can down this voltage

When the high logic is obtained at the gate pin then at drain pin of MOSFET Logic low value (Logic Value 0 ) is obtained .

3.SPECIFICATION OF MOSFET SUPPLY ON MOTHERBOARD :

· The specification of motherboard is that voltage is low and current is high .

Example of line voltage :

12v , current dissipation is approximate 2 to 3A.

5v, current dissipation is approximate 1A .

3.3v, current dissipation is approximate 4A.

CPU uses between 1.5v but current dissipation is approximate 10A.

=>thus power MOSFET of motherboard uses low voltage but need much current dissipation . For replacing this monitor power MOSFET cannot be used which are established at motherboard .

Example 1: Information of number of power MOSFET at motherboard .

- Voltage tolerance is only 30v is between the D-S.

- Till 42A connection is obtained through the D-S.

Example 2: Power MOSFET IRF-630 which uses generally pressures vessels of monitor . Which have following parameters : voltage 200v which is given to DC but only 9A current in line ?Power Impedance DS is low 4 ohm compare to 0 ohm .

3.INFORMATION ABOUT POWER MOSFET :

6.FAQs:

Q1: For what purpose power mosfets on motherboards are generally used ?

Ans. Following circuits are used in the Power mosfets on motherboards. Voltage regulator circuit , voltage regulator circuit for CPU (VRAM circuit ) , power voltage regulator circuit for chipset, voltage regulator circuit for RAM , voltage regulator circuit for video cards.

Q2. Power mosfet on motherboard are damaged because they work in description and crupts power line, when the voltage components are beings short supply by mosfets ?

Ans : When the RAM or RAM’s pin are short the vcc , then power MOSFET ,connected for RAM voltage are short or burst .

Q3. What should do when the power MOSFET on board burn of damaged ?

Ans. If there can be shorted in the power MOSFET VRAM circuit or RAM voltage regulator then ATX power fan will become off after moving one or two times

- In this condition when supply power MOSFET of RAM becomes or burn , then long beep is received to the RAM for switch OFF , which will be the cause of VVC power fail .

- When the top MOSFETS of RAM becomes shorts then RAM voltage are increased and RAM continue damaged

1.PLACE OF VRAM CIRUIT ON MOTHERBOARD

à What is VRAM ? VRAM (Voltage Regulator Module ) is Stable voltage circuit for CPU.

-VRAM circuit (Voltage Stability for CPU ) generally placed in-front of CPU socket . There are following components in this circuit :-

-PWM IC(VRAM chip )

-Phase Driver IC

-Power MOSFET

-Coli

-Filter capacitor

Function of VRAM circuit provides a constant according to current of CPU for CPU power supply .

2. LOGIC CIRCUIT DIAGRAM OFVRAM MOTHERBOARD:

à Main components of VRAM circuit :

-PWM IC (Pluse PWM –Pulse Width Modulation ) :- Oscillator works for controlling the Pairs work of power MOSFET .

-Face driver IC : It is divide the opposite two range

-Power MOSFET : Its activity is done according to PWM pulse control signal , when positive pulse of pulse is received then MOSFET becomes ON and when negative pulse of phase is received then MOSFET becomes OFF.

-Coli : For filtering the DC voltage pulse in the DC voltage , It is connected with the Capacitors.

-Capacitors : For filtering the DC voltage pulses in the DC voltage , It is connected with the coli.

à Working principal of VRAM circuit :

-When supply is received at P Good (Pin Press ATX Power Problems) without any Up /Down in the VCC voltage then PWM IC will generate, It is generate three pairs of PWM1, PWM2 & PWM3 for MOSFET .

-When this PWM pulse passes from phase drive IC then divided into two pulses with opposite phase that time opposite control pulses are given to the gate of phase -2 powers MOSFET.

-When power pulse is positive then MOSFET drivers becomes ON. it has power control pulses which are break and oscillator frequency of PWM pulses continue shut down the power MOSFET .

-In each phase one pairs MOSFET is used , by which alternate phase is received , according to the received phase , one voltage pulse is generate in between the MOSFET .

-Through voltage pulse filter circuit

à Specification of VRAM circuit :

-This is converting the 12v into 1.5v and low current to high current . it obtain the 16 phase voltage convertor circuit from the phase 2.

- Very low losses of capacity in then self circuit . which is approximate only 20% of effectively capacity .

- In VRAM , there is ability the CPU voltage level signal in the automatic shape according to logic at VID1, VID2 ,VID3 and VID4 pins according to the report received from CPU.

- CPU does not add the value of VID pins 1 on Pentium 4 motherboard and by defaults logics circuit provide the 0v VRAM voltage .

-There are 4pin connector for 12v Input to the VRAM circuit of motherboard

Details of PWM pinsLoscillation IC) :

-VCC –power supply for IC .

-PWM1 , PWM2, PWM3: This is pulse width modulation for controlling the lead pair of power mosfets .

-ISEN1, ISEN2,ISEN3 : Pins of current sensor

-EN_IC-pin for operations .

-ENLL(PGOOD pin ): ATX power station operates correctly.

-VID0,VID1, VID2 , VID3, VID4 pin : status logic voltage value for uses of CPU .

- PGOOD ,OVP : VRAM circuit status of south chipset .

-VSEN –voltage sensor (feedback pins )

3. VRAM CIRCUIT OF MSI MOTHERBOARD :-

4. SIGNALS CIRCUIT, GIVEN TO THE VRAM CIRCUIT AT SOUTH CHIPSET

-When the VRAM circuit is correct for CPU and CPU is ready for working ,then signals are out from the VRAM circuit for south chipset then VRAM is working properly which is known as VRAM_GD (VRAM GOOD).

-This VRAM_GD signal is used as a condition for reset the south chipset system . If VRAM circuit does not working properly or there is same problems in it then VRAM_GD signal dos not obtain to south chipset and thus signal is not reset for boot .

5. TESTING METHODS OF VRAM CIRCUIT – (TESTING FOR CPU SUPPLY ):

When the voltage level is test for CPU then the following points to be noted given below :

-CPU vCore voltage can be check without connection the CPU at CPU socket in the Pentium3 motherboard

-For testing of CPU supply we need to plug CPU in CPU socket in Pentium4 motherboard , after this you can check the voltage. if there is no CPU in VRAM circuit in main pen 4 then the voltage is by default is 0v .

-We need to test v core voltage before connecting the CPU socket for testing the CPU voltage and prevent from the shorts of VRM circuit mosfets because the increased voltage can damaged the CPU .

6.POSITION OF TESTING THE V-CORE VOLTAGE

- Please measure the v-core voltage (voltage for CPU) which is test between the starting by the DC Coli , you can be measure on coils , if the supply voltage id approximate 1.5v DC then circuit is correct but if the supply voltage is 0v or less than 1v than VRAM DC is damaged .

For testing of CPU voltage level tests the positive on the top of the capacitor or inductor .

When measure the supply voltage sockets must be placed between the main boards Pentium 4 CPU for CPU and output voltage must be measure the starting (inductor must be common from 2 to 4 in output size.)

7. TESTING STE3PS OF VRAM CIRCUIT OF PENTIUM 4 MOTHERBOARD V-CORE :

Steps1: Measure the v-core voltage for 0v when the CPU is not attached , If this is not install already , when the v-core voltage CPU VRAM has been shorted then the greater then 12v voltage is obtain on the mosfets .

Steps2 : Install the CPU , switch ON the power supply and measure the v-core voltage on pin of coil.

-If the voltage between the 1.5v than circuit is correct .

-If there is no voltage or less than 1v, output voltage is low than VRAM circuit is damaged .

à Follow these steps and check after this follow steps:

Step1: (On the source and measure the voltage without CPU )

-Supply the power to the motherboard , supply the 12v regulation for on the v-core voltage ,and measure voltage on the top of the top of the inductor circuit of VRAM voltage stabilizer .

-Use the test card for checking the status of power source

-On the main switch for running the main switch (PWR pin shorts) . if the 3.3v,5v, and 12v lamp is on on the ATX light of test card than card i.e. main board is not shorts .

-Measure the 0v on pin of inductor . (CPU VRAM output voltage circuit defaults =due to 0v).

à =>If the CPU voltage is not obtaining and 5v to 10v voltage are obtaining the top of the inductor than the mosfets circuit is shorts . Test the mosfets with carefully.

à STEP2 : (on the power source and measure the volt on CPU in socket , which are established on the main board.).

-Install the CPU in socket on the motherboard . (be sure that CPU correct .)

-Power the motherboard ; supply the standard 10v DC v-core voltage to voltage regulation

Measure the voltage on the top of inductor circuit of the VRAM voltage stabilizer .

- Use the main test card for testing of status of power sources .

- - On the main switch for running the main switch (PWR shorts legs ) . And measure the 3.3v, the 1.5v on VRM circuit ofr the CPU voltage .

- If that measure we obtain the 0v (V core voltage 0 than VRAM circuit is not active .

à You need the following methods for correcting the circuit :

- Dry the vacuum oscillation pulse PWM IC and PHASE .

- Check that there is any shorting in the MOSFET .

- Change the PWM Pulse oscillation IC.

CHAPTER -4

CHIPSET POWER SUPPLY

- North chipset uses the 4VCC , in which two for south chipset and two common voltage for CPU ,RAM

- 5 lines south chipset voltage are used with 1.5V and 1.8V south chipset voltage . Among these three Voltage STB5 , 5V and 3.3V are directly received from the ATX source.

2.IDENTIFICATION OF VOLTAGE STABLIZER CIRCUIT FOR MOTHERBOARD CHIPSET :

The selection of right voltage stabilizer circuit for motherboard chipset becomes complex due to following reasons –

- Chipset in pins cannot be measure by using the any pin clearance .

- - There are Printed Insulated Circuit backside of the chipset is painted by the paint .

- -In the life time of many motherboards uses the many voltage stabilizer circuit .

- Many different voltages are used in different types of chipset.

à YOU can identify based on the following characteristics specification :

-For two chipsets voltage stabilizer circuit generally placed area between the both chipset .

-When they work than supply pin at 1.5v and 1.8 v .

- 8pin IC used for control the MOSFET circuit .

- Some new motherboard are used at the [power source of CPU . So these are the coils circuits. .

Measure the supply pleased between the chipset of power mosfets which is 1.5v or 1.8v , which is power voltage stabilizer for chipset .

3. VOLTAGE ST^ABLIZE CIRCUIT DESIGN BY THE OSCILLATION DRIVER SIGNAL POWER IC MOSFETS :

- Output voltage can be changed by changing the value of resistance by using the feedback circuit which is imposed on the need of distributions .

· Operation principle of circuit :

When supply is given in it then the voltage stabilizer IC , generate the control voltage for G pin of MOSFETS . This generated voltage obtain on gate pin of MOSFET than MOSFETS provide the 1.5v voltage for supply load, this is for supply chipset , In the electrical circuit , Voltage received at source pin of power MOSFETS are given to the feedback pin of IC for controlling through the resistance R106 and R107 . If there is increasing in the output voltage of any reason then the value of voltage at feedback pin in increases . So the IC will provide the control signal as automatic for decreasing the voltage ,by which output voltage are decreased . When output voltage are decrease then control process works its opposite .

In this circuit , there are adjustable voltage from 1 V to 3 V , when we change the value of resistance R106 , R107 for distributing application , which is changing the feedback voltage of FB pin of the IC .

2.Voltage Stabilizer Circuit Designing by using the Amplifier IC Power MOSFETS Control Algorithm:

Used in the Voltage Stabilizer circuit for Chipset and RAM Power Source .

· Description of Circuits :

- - Zener diodes which are connected to pin no .10 of IC generate the voltage of opposite standard .

- Pin no. 4 is VCC source pin

- Pin no . 8 of IC is used for ON the DC voltage power MOSFETS .

· Principle of voltage :

- - Voltage are fixed of Pin no .10 of IC by using the Zener diodes , reduction voltage are obtain at th pin no .9 , then voltage are obtain at the pin no . 8 of IC .So the output voltage of power mosfets is low .

*Suppose there is increasing in the load current consumption then output voltage are decreasing . After this , feedback voltage will decrease at pin no . 9 and the principal of algorithm , result will be be received in the increasing flow for increasing in the power load .

Voltage stabilizer circuits by connecting two circuit:

- For increasing the quality of output voltage, the circuit can be design by connecting the two circuit . As shown in the circuit .With this type of circuit , one power voltage will decrease the voltage through the DS of stabilizer circuit , by which it decrease the power , which should be feel by it .

If we want to change the output voltage than we can change the value of resistance R173and R174.

5. Voltage Stabilizer Circuit design by using the voltage IC , LC filters and drivers :

- This is principal circuit of voltage stabilizer circuit , which is operating similar to VRAM circuit (voltage stability circuit for CPU ) . This circuit generally used in high quality motherboard circuit . from this motherboards obtain the more life .

- IC-RT9214 used in circuit is 8 pin IC. ( As shown below in fig with operation principal)

Pin no.	Name of pin	description
1.	BOOT	This is supply pin for upper gate drive department ,
2.	UGATE	This is upper gate driver output pin of IC , which is connected to gate of high site power
3.	GND	This is the ground pin of IC .
4.	LGATE	This is lower gate driver output pin of IC , which is connected to gate of low site power mosfets .
5.	VCC	This is positive supply pin of IC , which is operate at 5V to 12V .

Voltage stabilizer circuit design by the feedback voltage stabilizer IC

- It is similar to power MOSFET IC and driver IC , which is capable of feedback pressure LM-1117

- The principal operation of this IC is very simple . The circuit diagram of this IC is given below ; you are making the constant voltage .

- In the output voltage , as you want for changing like the same , you can generally change the value of R2.

But line is not increased , this circuit only secondary voltage like 1.8v voltage for chipset used only for control .

· General question and answer about the chipset voltage stabilizer circuit :

Q.1What will be happen if the voltage stabilizer circuit of motherboard is break ?

Ans :- if voltage stabilizer does not working for for the chipset (i.e . . chipset not getting the 1.5v or 1.8 v supply, then chipset will not work , by which motherboard will not boot , no information will be obtain by the beep on the screen , but at this time pop open source also working from which fan is moving .(Due to 5v STB supply by the open circuit voltage ).

-When you check this you will see that the main card test test RST lamp is continue on or off. (it is the result of when all the carefully are loosed ).

-If the is mosfes being shorted =>Then this provided the 3.3v or 5v both voltage ,chipset which is warm and damaged after some the operating .

Q.2 How you will decided that who are the power mosfets voltage stabilizer of chipset power

Ans :-Pin of chipset , which gives the power to the chipset . They are elevated so this can not be measure . But this can be done based on various features .

- Voltage stabilizer circuit generally placed between the areas of two IC for the chipset .

- 3.3v voltage is obtained at pin D of power mosfets .

- 1.5v (with Intel ) DC or 3VDC (for VIA chipset ) voltage are obtained at pin S of power mosfets of voltage stabilizer circuits.

Q3. What is the reson of damaged thj=e south chipset?

Ans:- The reason of damaged the south chipset is as following :

-Chipset –due to short of 5v, 3.3v or line source.

-When system is not reset from our signal .

· Details of shorts chipset are as follow:

If the chipsets is warming , before the power switch becomes ON or after the ON –Chipset is vary hot (heating produces by toching the hand )

=> This is describing that south chipset is shorts and At this time you need to change the suth chipset .

When the good chipsets work than the heats of this chipset is 40*C.

*signal does reset the south chipsets .

- When the south chipset does not emit the reset signal than motherboard is dead .Loss of reset signal is done by the test card . . When the reset signal is not obtain than north chipset does not work and also other components does not work . Mother is not boot and display will not be obtained.

Reset signal system can be tested by the test card main . If the reset signal is lost at the main than the system chipset north , CPU and other components can not work . So the motherboard will not boot ,information will not reached there that what are happening or neither screen will be obtained .

After some time to operates system will display the reset signal (PCI RST #).

Damaging of reset (Like –No Light or Bright Light Reset but No Short) produces due to the followings of south chipset , for example :

- Not obtaining the 1.5v or 1.5v power supply for the chipset (Broken Circuit Stabilizer )

- ATX power failure for mail chipsets , from which PG voltage are loss (signal sources incident ATX ).

- Problem in VRAM circuit (CPU voltage ) or CPU signal is not obtaining the VRAM-GD south chipset

- Pines of south chipset are broken or dry sold .

Reason of damaging the chipsets:

-Direct use of chipset voltage STB5v, 5v,3.3v, when we use the low quality ATX this is directly affect the chipsets or failing of ATX power. Thus the reason of failing of south chipsets is mainly ATX source .

-South chipset driver components like extension card on PCI slots drive on the IDE slots , USB ports . So if the sounds cards or devices , like hard disk drive failure with the line the signal sources from shorting than the south chipset is damaged .

CHAPTER -5

POWER SUPPLY OF RAM

1.Voltage for RAM

RAM Type	Used Voltage	Even	Voltage Stabilizer Circuit
SDRM	3.3V	168	not
DDR	2.5V	184	have
DDR2	1.8V	240	have
DDR3	1.5V	240	have

2- SDRM work at 3.3V , these voltage are available already on the motherboard , SDRM does not required the voltage stabilizer circuits .

- DDR, DDR2 and DDR3 RAM need the voltage below the 3.3Vand 5V so this voltage need to down the voltage by using the voltage stabilizer circuit this iow voltage is given by according to need .

3.LEG OF DDR VOLTAGE SLOTS :

Power supply pins of DDR slots – voltage 2.5V

-DDR slots are 184 pins , required voltage level is 2.5V for DDR slots and pins of power sources for DDR slots are shown above , which have many member of pins.

(7,15,22,30,38,46,54,62,70,77,85,96,104,108,112,120,128,136,143,148,156,164,168,172,180,184 including these pins )

NOTE : counting ‘s of pins is , as shown on DDR slots RAM are divided into two zones , a long slots are on the left side and small zone on the right sides , counting ‘s of pins are start in row wise like 1,2,3……..92 . After this we start left to right serial 93,94,95……184.

4.VOLTAGE PINS OF DDR SLOTS :

-DDR2 slots power supply voltage is 240 pins IC , 1.8V voltage for DDR2 (above circuit diagram show the DDR2 slots ).

NOTE : counting’s of foot of DDR2 slots , as shown above ,RAM is divided into two zones ,at the left side , for a long segment of DDR2 Slots , at right side , for a shorts zone , In the first second row counting from left to right from serial 1,2,3……to 120 , after that count left count left to right in the row from 121,122,123…….to 240

5.Voltage leg of slots DDR3 :-

-There are 240 pins in DDR3 slots . Power supply of DDR3 slots have the 1.5V which is shown in above of slot fig .

NOTE : Counting’s of pins , as shown at DDR3 slots RAM is divided into the two zones the right side zone is longs and left side zone is small zone , pin counting of slot ,from left to right serial 1,2,3….120 & counting of second row left to right , from 121,122,123…..to 240.

6. Lcation of power source voltage stabilizer for RAM :

-Generally , power MOSFETS and controller IC of stable voltage circuit connected , near about RAM slot . Working procedure of this circuit is totally the same like the circuit of chipset voltage stabilizer .

7.RAM power source voltage stabilizer circuit of gigabytes motherboard 3i845PE:

Power control IC –W8833301 used for RAM and power MOSFETS components placed around the RAM slots In the I-W-83301 three port control are used .From which for 2.5V volt stabilizer circuit output port is used for RAM.

The out drive pulse on the gate of MOSFETS Q1 are given to he pin no.20 of IC-W-83301.2.5V volt is out by the MOSFETS Q! For DDR .

8.Method of decides of voltage stabilizer circuits for power MOSFETS RAM :

--When we see many power MOSFETS for RAM

-For this easy method is that check the resistance around the RAM slots of power MOSFETS’s pin S. From which MOSFETS source show the 0 value of resistance , that is power Voltage Stabilizer for RAM.

If the 0E impedance between the RAM power pin and the MOSFETS source pins than this is power voltage stabilizer circuit for RAM .

If the impedance is more than 0E between he RAM power pin and the MOSFETS source pins then that is not power voltage stabilizer circuit for RAM.

9. General question and answer about the voltage stabilizer circuits for RAM :

Q.1. What is show the machine when there is no power supply for RAM ?

Ans: When there is no power of RAM at the time of booting then the machine show the continue long error beep and nothing will be obtained on the screen of the computer .

Q.2. How will be decide early that where the power supply circuit of RAM ?

Ans: For deciding the power voltage stabilizer circuits of Ram you will check the power pin of RAM (VDD pin ).

It will be decide to checking the resistance by MultiMeter Resistance at source pin of power MOSFETS connecting around the RAM Slots and between the power supply pin of RAM slots .If the 0E resistance is obtained from any power MOSFETS then that is power voltage stabilizer circuits for Power MOSFETS RAM .

Q.3. How will be decided of power MOSFETS driver for RAM voltage stabilizer ?

Ans: Measure the resistance at G and S pin of RAM power supply MOSFETS and at the IC near about the RAM Slots .From which pin of , 0IC impedance is obtained , that is the MOSFETS Driver IC.

For example : Pin to pin is connected through the drive IC in the below circuit of G and S pins

Q.4. if the RAM power is loose then machine is boot but cannot be fast , why ?

Ans : losing of power supply voltage machine is constant in boot condition and error beep message is obtain from the speakers .

- Although some condition is that in which motherboards , computer is not boot after checking the status of voltage stabilizer circuit for RAM .

If the voltage stabilizer circuits make the new signal for RAM PWR_OK which is provides the PWR_OK Resets signal to the new system of south chipset .

RAM voltage stabilizer circuits made by using the IC ISL6625 and two MOSFETS is signal report logic controller at pin no . 15PG_VDDR .If there is power loss for RAM then PG_VDDR signal will be loss ..It prevents the logic circuit and PWR_OK (good source levels) signal will not generate by which chipsert does not generate system reset signal .

Controller Logic testing signals are follows on some motherboards :

PWROK_VRM : Good for CPU supply voltage stabilizer circuits

PWROK_ATX        :    ATX power source works properly .
PG_VDDR                                :    Good for RAM voltage stabilizer circuits
PG_V1V5                  :    Good for chipset voltage stabilizer circuit

Now , there are four full power good signal at new logic controller , which is given the PGood South Chipset generate the Reset Signal ,which is given to all.

Source Voltage Stabilizer Circuit for VIDEO CARD APG 4X, 8X:

1- Supply voltage AGP Video cards :

- 3.3V voltage are given to AGP 1X ,2X video cards , so the voltage stabilizer circuits is not needed which is use the 3.3V directly on motherboards .

- AGP 4X and 8X video card uses the 1.5V supply voltage . So , there is need a voltage stabilizer circuit for down the 5V supply to 1.5V or 3.3V for AGP card .

CHAPTER -6

Clock Generator Section

1.Working of clock generator circuits

(i) Clock Generator (Clock Generator –Clock Circuit Pulse )

- Clock frequencies are know as computer owners .It is correcet in case of time , so this is called the clock , which is clock time .

(ii) Meaning of clock pulses on computer :

-Clock is very important on computer , this is move below for describe the Value of data .If clock pulse is not move with serial data than this is meaningless .

-Digital signal processor IC does not work without clock in some system , so clock is compulsory for IC so that computer work correctly .

- Meaning of clock that synchronies the data of computer

2.Location and Characteristics of clock generator circuits

(i) Location of clock generator circuit diagram on theoretical diagram :

- A clock generator circuits diagram on theoretical diagram :

-A clock generator circuit does not depend on other components of motherboards . This is design by theoretical diagram . This is first operation after main supply sources and provides the different clock frequencies on different components .

(ii) Placing of clock generator circuits on gigabytes motherboard:

Clock pulse circuit –IC circui with clock Generator 14.3MHz quartz stand at gigabyte motherboard

(iii) characteristics of identification of clock generator circuits on motherboard

- Watch a IC on motherboard which have oscillator (14.31MHz) of 2 pins and generally 2 sides pin in this IC , from which identify the clock generator circuits .

- -Pins of IC clock generator circuits on ASUS motherboards are in two lines and 14.34MHz crystal oscillators are placed near this IC

3.Operation principle of the clock generator circuits (clock pulse circuits ):

(i) Logic circuits diagram of clock generator circuit :

Specification of clock generator IC:

Vdd : 3.3Vpower supply .

FS0,FS1 and FS2 : Select pin for CPU clock frequency .

CPU STOP : Clock signal of CPU to stop the operation .

PCI_STOP : Clock signal of PCI to stop the operation.

PWRDN# : Signal power off.

SDATA : Exchange data with south shipset and RAM

SCLOCK : Talking clock .

PWE_GD# : Reporting signal about the ATX power voltage stabilizer circuits and motherboards .

XTAL : oscillator pins .

CK_CPU : CPU clock supply .

CK_MCH                     :               Clock for north chipsets.
CK_AGP                      :               Clock for video cards .
CK_ICH                                       :               Clock for south chipset .
CKFWH                      :               Clock for RAMBIOS.
CK_LPC                       :               Clock pulse Sio-IC
CK_LAN                      :               Clock for on broad networks card ICs.
CK_MPC                     :               Clock for PCI slots
CK_SLOTS                 :               Clock for PCI slots
CKM_1M                    :               Clock for south chipsets IC,SIO and video cards .

(ii) Operation principle of clock generator circuits :

-When the supply 3.3V is applied at the VDD in IC of circuits then the pulse oscillator circuits operate and generate the 14.318 MHz standard frequency . After this , this circuit will generate manyn clock pulses with the help of standard quartz . After this to provide the clock pulse on motherboards of different components they are divided into different definite percentage .

NOTE :

VttPWR_GD#- This is obtained by collects the logic clock circuits of signal PG.( PG power good signal infrom about the ATX).

VRAM_GD – Information about the CPU voltage stabilizer

PG_VDDR- Information about the voltage stabilizer circuits for RAM .

PG_V1,5V- Information about the voltage stabilizer circuit for chipsets

If the problem is occurs on 4 departments of ATX ,VRAM circuit’ chipsets voltage stabilizer circuit ,and RAM voltage stabilizer circuits than the signal pulse is not obtained and pulse VttPWR_GD# does not work.

Thes circuits inform about the pulse clock IC and control the south chipsets for voltage stabilizer circuits . When this voltage stabilizer circuit is failed => than signal PWR_GD is not obtained =>clock

Generator and chipsets will not work .

4.Methods of repairing the faults and testing

(i) obtain features onmachine when the clock pulse generator circuit is breaks :

- Before testing the clock IC ,checks the ATX power supply (main source ), VRAM (CPU Voltage ) voltage stabilizer circuits , RAM voltage stabilizer circuits and chipset voltage stabilizer circuits on motherboards .

- Clock circuits provide a pulse for other components of motherboard . For CPU chipsets ,,north south chipsets , Sio ,ROM BIOS , AGP SLOTS PCI IDE……….

Thus, when the clock generator circuit is break then the motherboard will not boot , fan will be turn but source computer will not boot then the information is not obtain neither the sound nor on screen .

(ii) Testing methods of clock pulse : -Use of main of main test cards , connect the power supply at motherboard and Test cards on PCI slots and switch ON the power , check the status of clock light (when you check the clock then there is no need to connect the CPU at Pentium 3 motherboard , but there is necessary to connect CPU at Pentium 4 motherboards .)

NOTE : Before connecting the CPU on motherboard , you should to check the v-core voltage of VRAM circuit for damaging the CPU from high voltage .

*(Short the power switch plug pin with screw driver made on the front panel for making ON the motherboard)

2.1Where the good clock pulse is obtained from circuit test :

When Light is Light Up (Light maintenance) at card test main CLK then following information are provided

- Self clock generator which is working on the motherboard.

- Atx Powe supply for CPU VRAM voltage stabilizer & other circuits generally working properly .

2.2 In the condition of clock pulse not received then test following type , where the bright light is not received in testing by main test card then this is done due to damage tha tracks in the clock generator circuit .

- Solder the IC pin .

- -Due to breaking of 14.31MHz oscillation .

- Damaging of IC clock generator circuits does not work .

2.3 When the CLK bright light is obtain for sometime (10 seconds) and after this is off.

It is occurs due to one of them .

-ATX power fail => PG voltage is not obtained

- VRAM circuit (CPU Voltage ) is not working or providing wrong voltage => VRAM_GD signalis not obtain

- Problem in voltage stabilizer circuits for RAM (only few new pulse are obtaining ).

(iii) In this solution clock pulse is obtained .)When the tested is performed by the test main cards then CLK not gives the bright light ).

Reason :

It is mainly occurs due to tha damaging of tracks in lock generator circuits

-Solder the IC pin.

-Due to breaking of 14.31MHz oscillation .

-Damaging of IC clock pulse is not obtained .

Repairing :

- Identify the location of clock generator circuits .(See the IC on motherboards in which pins in two sides and 14.318 MHz oscillator are placed , that is clock pulse IC and pulse clock generator circuits ).

- -Clear the area around the IC .

- Use the hot air gum for removing outside the pulse clock IC .

- Similarly do for 14.318MHz oscillator.

- Before changing the clock pulse IC ,it is essential to test with test card again after each work .If the clock light is obtaining than the clock is obtaining .

(iv) In this solution clock pulse is obtained .(when we use the main test cards than the CLK gives the bright light for some time and after this it is off .)

Reason:

This is occurs due to following reason :

-Losses of ATX power by which clock pilse is not obtained .

-Losses of VRAM circuit voltage problem due to VRAM_GD or you are not connecting the motherboard CPU.

-14.318MHz are not obtaining at Quartz oscillation circuits .

-Dry sold of clock IC.

Repairing :

-Check the ATX power .

-Placed the CPU in Motherboard and check this .

-Check the circuits’ voltage and check the VRAM voltage for CPU core .

-Change the 14.318MHz oscillator .

- Dry vacuum the pulse clock IC.

i. Clock pulse for PCISOLTS .

2.Faults and repairing methods of clock pulse circuits:

(i) Description : on the computer power switches . Fans move power source , machine is not boot , sound is not obtained the speakers and nothing is obtained on the screen .

Reason : This fault occurs due to following reason :

- Faults in clock generator circuits=> clock pulse are not obtained for components at motherboards .

- -Power supply not obtaining due to faults in VRAM circuits .

- Faults in chipsets power supply

- Due to faults in south chipset system is not making the resets signals.

- CPU pins are not properly connecting to the CPU sockets.

- ROM IC is damaged or BIOS program crupts

Checking by serially :

In this fault we first check the clock pulse .For removing the problem of the clock pulse we use the new clock IC.

Methods of testing :

- For testing do not place CPU and ROM on the motherboards .

- Fro supply he motherboards connect the motherboard from 20 wires and 4 wires .

- Mount the motherboard test card on PCI slots .

- Shorts the PW main switch by using the screw driver .

- Check the CLK light on motherboard test cards .

ð If the clock light is bright than clock pulse is obtained .

ð If the light is off than the clock pulse is not obtained . Track of clock generator is damaged .

Check that the clock light is on => clock generator circuits is correct .

Check that the clock light is off => clock generator circuits is damaged

(ii) Repairing methods :

- Clear the clock pulse from around .

- Resold the IC using the hot GUN .

- Testing the 14.318MHz by changing .

- Change the clock pulse generator IC .

Check the result after the each operation .

CHAPTER -7

RESET SIGNALS

What is the reset signal ?

-Reset is a English word which meaning is that “do again” .

- When the reset signal is on in the digital signal processing .

-If you press the reset button in a computer than will be reboot .

- Reset signal have two meaning in a digital circuits.

-Reset signal to start the operation . – Reset signal to again start the operation.

Example : When runner was waiting for running and referee give the signal for running . Hear referee work as a reset signal for runner , similar to digital signal IC .

2.Condition for processing operating the IC :

Addition of computer digital signal processing is known as IC number in other devices .To operate these IC following condition are required .

-Required voltage level is VCC .

-Required Clock pulse

-Required reset signal .

When the reset signal is obtained than the IC start operates .

- When the Required voltage and clock is obtained to IC than IC ready to operate , but when the reset signal is obtained than IC start operates .

- Restet signal is an electrical signal which is alive only 0.5 seconds.

3.Reset generator circuits on motherboard:

-System Reset signal on motherboard is generated by the south chipset , but to make this signal there must be south chipset factors as shown below .

- South chipset work well itself (In condition required like VCC.)

- The pin of CLEAR CMOS jumper must not be blank . CLER CMOS jumper set on normal position .

- South chipset must be obtained the signal from PWR_OK logic signal circuits .(This signal only obtained when the ATX power voltage stabilizer circuits operate correctly on motherboard).

Conclusion

- ATX power supply gives the PG (power good ) signal for good status . This is obtained good source status through the ray wire on motherboard .

- This source status signal pass through the logic circuits for generate PWR_OK signal of south chipsets .

- PWR_OK signal is a signal which is good for status sources . When the signal is obtained to south chipset than this is generate reset signal for system .

- Soth chipset need various supply like 5V, 3.3V ,1.5V, 1.8V . when from these voltage no one voltage than the chipset does not work.

- For operating the chipset there is needed of around the clock frequency .

- If the CLEAR CMOS jumper is a out than the south chipsets does not make the system resets signal .

ð System reset signal is a signal which is gives the reset signal to the components of motherboards , north chipset , ROM BIOS < PCI SLOTS CARD , Sio-IC ,IDE ,connectors b, disk drive, video cards , lane controller IC etc .

4.Reset signal generator circuits system of motherboard:

- Reset source circuits of motherboards is shown in fig .PWR_OK or P.GOOD signal is generated by the status of ATX power logic , Logic status of power supply of chipset and AGP card , Logic circuit .

-When the output signal of logic circuits receive to PWR_OK or P.GOOD south chipset then it is generate the chipset reset signal for booting the motherboard system components .

-This system reset signal is obtained to north chipsets and other components .

-When the North chipset reset signal will obtained then for north chipset CPU ,CPU_RST signal will generate for launching the CPU activity , by which CPU will work similar active components

NOTES : Logic circuit are generally internally design in the south chipset and Sio-IC . Some motherboards use the IC specific logic ; these are known as Glue Logic.

5.Condition of south chipset for system reset signal :

Details of signal :

-GD_V.5V SINGAL : Meaning of this signal is that 1.5V stabilizer circuits is correct .

-P.G.( Power good ) signal : Meaning of this signal is that ATX power source is correct , this signal is obtained from gray wire of AX power supply.

-VRAM_GD signal : Meaning of this signal is that RAM power supply .

-GD_VDDR signal : Meaning of this signal is that VRAM power supply source voltage stabilizer circuit is correct . This circuits work for RAM power supply .

-Logic circuit are generally internally design in the south chipsets and Sio-IC . In which logic circuit different IC uses, these are known as Glue logic.

-PWR_OK (source is ok) or P.GOOD (source was good) only obtained at that time when all the signals are OK, if the circuits have weakness of one signal from four signal then the circuits does not provided the PWR_OK or P.GOOD signal .

To active the south chipsets power source VCC ,+1.8V, .5V and clock pulse must be obtained .

When the south chipsets PWR_OK signal and CMOS clear are normal obtained then the south chipsets generate the resets signal and reset the system for lunching the components on the motherboard .

6.Cause of loss the resets signal on motherboard :

Cause are followings :

-Plug is not connected in Clear CMOS motherboards .(1)

- 1.8V Power supply is not obtaining to chipsets (2)

- Damaging of clock generate circuits . (No getting a clock pulse).(3)

-1.5V Power supply is not obtaining to chipsets (4)

-ATX PG signal is not obtaining from gray wire on motherboard.(5)

-Failing of VRAM circuits. (Not getting VRAM_GD signal ).(6)

-CPU is not connected on motherboard –VRAM circuits does not working. (7)

-Faults in voltage stabilizer circuits for RAM or AGP cards (8)

7.Testing methods are as follow :

Testing methods are as follow :

-Ready the motherboard for checking the reset signal (CPU is not connected permanently ) .

- Use the good ATX power supply for motherboards .for

-Mount the motherboard test cards on PCI slots.

-To on power source shorts the pin of power switch by using the screw driver . ( String sockets switch ) .

· If the fan of ATX power supply are normally on => than you can say that there is no shorting on motherboards.

-V-core voltage is 0V until the CPU is not connected on the motherboards. So VRAM circuits do not work .( In some motherboards VRAM circuits work without CPU ) .

-Connect the CPU in CPU sockets. (When the CPU is connected than this start to make the power) .

-Check the clear CMOS that the CMOS jump0er is placed at normal position or not . Generally connected CMOS clear jumper , off the south chipsets .

- On the power source and check the “RST” light on the motherboard card test .

If the RST LED is glow and after some time immediately off than the resets signal is corrects .

- If the bright light is not obtaining than the retest signal (RST) is not obtaining .

If the light is continue ON (Not disable ) in the condition the retest signal is not obtained .

CHAPTER -8

CPU

1.OPERATION OF CPU :
1. CONDITION FOR OPERATING CPU:

-V-core voltage for CPU. (1)

-Clock pulse .(2)

-CPU_RST# signal (CPU start signal from north chipsets ) . (3)

-PWR_OK signal (Signal voltage stabilizer circuits which have good ATX source ) n(4) .

For reset signal there are four term on the motherboards , they must be obtained .

- With the connection of motherboard sockets , CPU connection must be good .(5)

- CPU must be supports the bus speeds . (6)

- CPU must be load the BIOS program .(7)

After the resetting motherboards , signal; system required three extra conditions (5) ,(6) ,(7) , which operate the CPU as shown above .

2. Methods of loading BIOS and CPU operation :

Description of startup process:

-When the power switch is ON => Power sources of ATX power supply, provides the operating voltage for Motherboard and provide the PG (power good) signal for logic circuits of motherboards .

- VRAM circuits voltage stabilizer (power supply circuits for CPU )gives the CPU V core operating supply voltage and VRAM_GD signal (Signal voltage stabilizer circuits gives the good VRAM )for logic circuits .

- Logic (Internally made in south chipsets or Sio or over logic IC ) signal will check the happening . (Testing logic signal is given to the logic circuits from chipsets and voltage stabilizer circuits of RAM in the new motherboards) . When the ATX power voltage stabilizer circuits work correctly then the PWRGD_ICH signal is obtained from form this logic circuits . (South chipsets obtained this status form this signal that the power resource are correct ).

-When all essential conditions are available then the South chipset out the retest signal for the system .

-System resets signal (PCI_RST#) are feed to the north chipsets and other components on motherboard .

-To start the CPU , north chipsets provides the CPU_RST# signal .

-To excess the BIOS , CPU uses the performance and signal .

-For launch the testing programs of computer components program of BIOS are loaded, CPU maintains this operation by using the BIOS .

3.When BIOS or BIOS error process are unable to loading :

Description of startup process :

- This process is similar to doing the boot , but when CPU load the signal , than due to corrupted BIOS ROM or BIOS Bugs ,CPU is failed . From this CPU stops the working after some seconds .

- Machine is continuously resetting without resetting , like repeating of signal methods .

4.Check the operation of CPU :

-What is necessary to known for us that is active or not , when the repairing of motherboard .

-CPU is active only when the clock pulse and signal pulse and system resets are obtained Because reset signal is obtained from the south chipsets to north chipsets . And north chipsets gives the resets signal for starts .

1.Methods of checking the operation of CPU :

You need to following steps for checking the operation of CPU :

- Install the CPU in motherboard . Connect the CPU heat sink temporary .

Note : There should be CPU of BUS support of motherboard .

- Connect the four wire connector (voltage stabilizer circuits for VRAM ) of power supply and 20 pin connector on motherboard .

- Install the Motherboard test cards on PCI Slots .

Switch and Check :

- Firstly ON the clock light lamp => Clock pulse are correct .

- After this RST light is on /off => Resets signal is correct .

- After this , see the OSC BIOS light , if both of these lights are glowing => It is show the activity andload of CPU.

BIOS program (Mainly two lights OSC and BIOS program or with turn off ) .

Following test show the good activity and CPU load BIOS program .

2. Due to following reason CPU does not work : (obtaining resets signal at one time ) :

Reset signal is obtained at CPU connected motherboard and it is not work that time (And test BIOS OSC light off) . It is due to following reasons :

- Motherboard CPU , do not supporting the BUS .)

- Connection of CPU sockets are broken (WITH Vacuum contacts )

- ROM_BIOS IC is not expose properly .

- BIOS program is failed .

- North chipsets is damaged and pin becomes dry sold .

3. Steps to solve the faults obtaining from CPU :

1. Motherboard CPU was supported to BUS speed

2. Check that the CPU sockets pin of motherboard is not broken

Check the Pins of Socket 775 carefully .

Clean the surface of CPU.

Removing the IC from Base Plug-ROM pins for butter results.

CHAPTER-9

SUPER I/O CONTROL SECTION

Main operation of this section is to control the keyboard, mouse , IRDA ,Parallel Port , and Comport (RS232) , FDD-Port , ACPI Interface section , Monitoring Interface sections . For this , this section is made by using the Input /Output controller chip . I/O controller IC is 128 pin IC and his IC is made by ITE , Winbond , SMBC , SMBD Company . The description of the section made internally in this IC is given below :-

FDC Interface Section

Main operation of this section is to interchange the data in serial way from floppy disk by controlling the 34 pin Floppy drive . In this section , spindle , slide motor is ON/OFF which is placed inside the floppy disk . The descriptions of pins of this section are as follow

Pin no . 1.: This pin is Density select output pin of IC . By this pin density is select of Drive A .Density = select the data transfer speed .

Pin no.2.: This pin is multifunction pin of input output . Selecting the density of Drive B by this pin and this is the BIT six pin of data output of general purpose input/output port B .

Pin no.3 .: This is the Index #Input pin of IC . Information of coming the Floppy Drive at Head Index File is obtained , by which Index File could be read .

Pin no . 4 : This pin is spindle motor signal output pin of Floppy Drive . By using this pin spindle motor is ON ..

Pin no. 5.: This pin is output pin of Drive select A. By using this pin drive A is selected . At this pin when high obtained then disable and when low is obtained then this select .

Pin.6.: This pin output pin of Drive select B. By using this pin drive B selected . At this pin when high is obtained then this select and when low is obtained then this disable .

Pin. No 7.: This pin is Spindle Motor on Signal Output Pin of Floppy Drive B . Spindle Moto becomes ON by this pin .

Pin no.8: This pin of IC is DIR Output pin by using this pin Head of Floppy Drive can be moved forward and backward according to DIR command. When high is obtained then head move forward and when low is obtained then head moved backward .

Pin no.9.: This pin of IC is slide motor output pin .Signals are provided to move forward of slide motor by using this IC.

Pin10.: This pin is Right Data Output Pin of IC ,.By using this IC write data are provided to floppy drive

Pin no .11.: This pin is Write Enable Output pin of IC . By using this pin internal section is enabling of this IC .

Pin.no.12.: This pin is tracking zero sense input pin . At this pin , head is informed the track is at zero during the format command of floppy drive .

Pin.no.13.: This pin is write protect Input pin of IC . At this pin protect signal are obtain during the floppy disk write protect. There is unprotect at this pin during the low and when low is obtained then this is protected .

Pin.no.:14.: This pin is read data input pin of IC .At this pin reading data is obtained form floppy drive

Pin.no.15.: This pin is head select output pin of IC . Side A & Side B of Head of floppy drive is select by this pin . When high is obtained then side B is selected .

Pin.no.16.: This pin is disk change input pin of IC . At this pin Disk change from Floppy, by which Index file of New file could be read . When there is High then Disk In and when there is Low then Disk Out massage is obtained at this pin .

· Faults finding and testing of FDC sections:

We are check this section at that time when connecting the floppy drive , floppy drive is not detecting and FDD cable , Floppy disk drive is ok then we will check this section following types :

1. Firstly in CMOS setup Enable the Drive A , Drive B of 1.44MB or according to floppy drive . If the setting is correct in CMOS setup then we check the low at the drive select pin of floppy drive . If the high is obtaining at this pin then check low at the DSA pin of I/O controller IC . If low is obtaining at DSA pin then check the track , in between I.O controller & FDD connector for open .

2. If there is High at DSA pin of I/O, after that floppy drive is not detecting then I/O controller IC is damaged. We will check or change the I/O controller ,

3. If connecting any Disk , Write Protect message is obtaining during the writing then check high at WP pin of IC . If there is low at pin then check Network Resistance , connected at this pin for open . If there is high at this pin , still WP message is obtaining then I/O controller IC is damaged , change it .

· Keyboard Interface sections :

Main operation of this section is control the normal and PS2 keyboard and PS2 mouse and interchanging the data. The descriptions of pins are as follow :

Pin.no.58. This pin is Keyboard Lock signal is obtained from Front panel of this IC . Ths pin is used in the Branded PC. In Assembled PC this pin is fixed for Unlock .

Pin.no.59.: This pin is A-29 gate output pin of IC . Data received from KBC Interface is reached at I.G.H.

through this pin .

Pin.no.60: This is Keyboard Reset signal output pin of IC .By using this pin Keyboard is reset.

Pin.no.62: This pin is keyboard Clock data input pin of IC. By using this IC operating clock pulse is given to the keyboard .

Pin.no.63: This pin is keyboard data input pin of IC. Data is obtained at this pin from keyboard.

Pin.no.65.: This pin is PS2 mouse clock signal output pin of IC . By using this pin operating clock pulse is given to the PS2 mouse .

Pin.no.66.: This pin is PS2 mouse data input pin of IC . At this pin data is obtained from the PS2 mouse .

· Faults finding and testing of keyboard controller sections :

We check this section at that time when the display is obtaining when the power supply becomes ON, but keyboard or PS2 mouse is not working then we check the following types:

If the keyboard is not working then first of all check keyboard connector for open of loose connection .If the keyboard connector is OK then check the 5V at VCC pin of connector. If there is no supply then check the jumper , connected in the supply line for open . If the jumper is connected between 2 and 3 then connect this between1 and 2 . If the supply is not for open . f the fuse is correct then check the coil .If the supply is correct then check the GND at ground supply pin of connector . If the ground supply is also obtaining still keyboard is not working then check the 4.5V supply at the data and clock pin of keyboard connector . If the supply is obtaining but keyboard is not working then this fault is due to I/O controller IC . Change it .

Note: Testing of PS2 mouse is similar to keyboard .

· LPC interface sections :

Operation of this section is controller all the sections made within the input/output controller section.

By which input/output controller IC comes in the working condition . The details of pins are as follow :

Pin no.18.: This pin is clock pulse input pin of IC. At this pin 24MHz to 48MHz clock pulse input is applied . Generally gives the 24MHz clock pulse at this pin .

Pin no.19: This pin is signal output pin of power management section made internally in the IC .By this pin PWM (pulse width modulation ) section is control.

Pin no .20.: This pin is volt source to source pin for internal section of IC . This pin is grounded .

Pin no.21.: This pin is PCI clock input pin of IC . At this pin PCI clock pulse is given from the clock generator .

Pin no. 22: This pin is Encode DMA Request signal output pin of IC . By using this pin any type DMA can be controlled .

· DMA

Meaning of DMA (Direct Memory Access) is interchanging of data without using CPU.

Pin no.23: This pin is Serial IRQ input/output pin of IC . By using this pin input sections are controlled made within the IC .

Pin no.24,25,26 and 27 : These pins are address and data control input/output pin of LPC bus interface sections .

Pin no.28 : This pin is positive supply input pin of LPC sections of IC.3.3V positive supply is given at this pin .

Pin no.29: This pin is clock pulse enable indicating input pin of IC . Information of clock generator becomes ON is come at this pin .

Pin no.30: This pin is reset input pin of CPU section made with the IC .LPC section is reset through this pin .

· Multi-mode parallel port section :

Main operation of this section is interchanging the data from parallel devices , connected in the parallel port . Meaning of Multi-function parallel port is interchanging of data from serial parallel devices on the parallel port . At Multi-mode parallel and serial both the devices can be connected, but at parallel port only parallel devices are used . There are parallel port in the P-I to P-III motherboard , But in the p-III, p-IV motherboard multifunction parallel port is used . The description of the pins of this section are as follow :

Pin no.31: This pin is Printer not floppy input pin of IC. By this pin serial and parallel port are selected . When the high obtained at this pin then serial port and when low is obtained at this pin then parallel port is select .

Pin no.32: This pin work as a paper end in printer mode . At this pin paper end message is obtained during the high . This is obtained during the high . This pin is work as write data out for external floppy drive.

Pin no.33: This pin is printer is not ready signal input pin printer mode . During the printer command if the printer is not ready then printer not ready massage is obtained . And this is spindle motor ON pin for external floppy drive .

Pin no .34: This pin is printer is ready signal to get more data input pin in printer mode . During the printing when fist command is completed then the high is send to input/output control for next command. And this is work as drive selects B for external floppy drive .

Pin.no35: This pin ids PD-7 data input/output pin in printer mode . And this is work as drive selects A for external floppy drive .

Pin.no36: This pin is PD-6 data input/output pin in printer mode . And this is work as spindle motor start pin for external floppy drive.

Pin no.37: This pin is PD-5 data input/output pin in printer mode .

Pin. no38: This pin is PD-4 data input/output pin in printer mode . And this is work as disk change pin for external floppy drive .

Pin .no 39: This pin is PD-3 data input/output pin in printer mode . And this is work as data read input pin for external floppy drive .

Pin no 40 : This pin is PD-2 data input/output pin for external floppy drive .

Pin. no 41 : This pin is PD-1 data input/output pin in printer mode . And this is work as track zero pin for external floppy drive .

Pin no 42: This pin is PD-0 data input/output pin in printer mode . And t his is work as index signal pin for external floppy drive .

Pin no 43: This pin is printer mode select pin in printer mode. Online or offline message is obtained from the printer at this pin. During low ON line message and during high OFF line message is obtained. Work as a Step(DIR) for external floppy drive .

Pin no.44: This pn is printer mode insulation input pin of IC . When printer is ready at this pin then Ready signal is provided to system . Work as a step DIR for external floppy drive .

Pin no.45: This pin is error detection input pin in printer mode. At this pin during printing command the printing data is not correct according to the

Pin no46: This pin is paper auto feed or manual feed input pin in printer mode . At this IC during low Paper Auto Feed & during high paper manual feed massage is obtained & this pin is Drive –A Drive –B select output pin for External Floppy Drive .

Pin no .47 : This pin is printer strobe signal input pin . At this pin during low information of connecting the printer with parallel Port is receive .

Pin .no 48: This is positive input supply pin of multifunction parallel port made in IC internally . At this pin 3.3V volt supply is obtained .

· Testing and fault finding of parallel port section :

This section is checked when the parallel device is not working after connection at parallel . this section is checked as follow type :

1. First of all check the parallel port for enable in CMOS setup and after that check the parallel for ECP, EPP mode . If there is Auto function in the C-MOS setup , then it will be set for Auto function .

2. If the CMOS setting is correct then we will check the low at PNF pin of IC . If the high is obtaining through PNF pin then parallel port , printer cable or printer is damaged .

3. If the low is obtaining at the PNF pin then check the logic at PD from PD pins . If the PD0 pins to PD7 logic is obtaining but parallel devices is not detecting then I/O controller IC is damaged .

· Communication interfacing section :

Main operation of this section is to control the serial communication devices like modem , Lan card Etc. and interchanging of data .

Pin no .48,78: Theses pins of IC are clear to send information input pin . Information is obtained when the send command is completed from communication devices at these pins of IC ..

Pin no 59 , 79 : This pins of IC are Data send to ready signal input pins . At these pins information obtained that transfer data send ready . Duration the low data set ready information is obtained .

Pin no 59 ,79: These pins of IC are Data send to ready signal input pins . At these pins information obtained that transfer data send ready . During the low data se ready information is obtained .

Pin no 51, 80: These pins of IC are Request to send output pins . Massage of Data Send Request to the Communication Device is send through these pins .

Pin no .52,81: These pins of IC are data terminal ready input/output pins . During the low at these pins data send and receive from communication devices .

Pin no 53 ,82 : These pins of IC are serial data input pins serial data is obtained from the communication devices .

Pin no 54,83: These pins of IC are serial output pins . By using these pins data is transfer from each other for send to communication devices

Pin no 55: This pin is negative supply pin of communication section made within the IC . This pin is grounded .

Pin no 56 , 84: This pins are Data Career Detect Input pins. This pins gives information that obtained data from communication devices are connected to career frequency .

Pin no 57, 85: These pins of IC are Ringtone Indicate input pins . Netork connectivity information is obtained at these pins from communication device .

· ACPI (Advance Control Power Interface) sections:

Main operation of this section is to control the stand by sections made in input/output controller . To ON this section 5V supply is provided from the Violet Wire of SMPS .This section is work during the shutdown and system ON . The details of pins are as follow :

Pin no 67: This is Power signal output pin of IC . By using this pin power signal is provided to green wire of SMPS.

Pin no 68: This is Power signal input pin of IC . At this pin power ON signal is feed from the power trigger switch .

Pin no 69: This is the battery volt input pin of IC . At this pin sample volt system is given by the battery of UPS ,from which Battery backup display the time of UPS system . At this pin battery voltage are given by 10Ω ,100 Ω, 1/4 Ω ,1/8 Ω resistance . This pin is used in brand PC not in assembled PC .

Pin no 76: This is the System Cover Open input pin of IC . At this pin when the system cover open then the system cover open high information is obtained . This pin is used in branded PC .

Fault finding and testing of ACPI interface section:

This section is checked when the system is directly ON when the power supply is ON (without power trigger switch press) or SMOS is not start when the Power trigger switch press and SMPS OR VRAM section is correct then we check the follow :

1. If the system is directly ON when the power supply is ON then first clear the CMOS by CMOS jumper . System is directly ON after clearing the C-MOS then check the transistor for short of I/O controller . If the transistor is correct or not connected then the I/O control IC is damaged . Change the I/O control IC .

2. If the SMPS is not ON when the power trigger switch press , but display are obtaining when the green wire is shorts then firstly we check the RTC section for ON . If the RTC section is correct then check 5V/3V supply of stand by section of controller . If the supply is not obtaining then check 0W resistance for open .

3. If the 5V supply is obtaining to stand by section but system is not ON when the power trigger switch is pressed then IC is damaged

NOTE : System is not ON when the negative point is replaced from the RTC crystal body .

· Hardware monitoring interface section :

Main operation of this section is sense and displays the temperature , CPU , cover voltage , system volt and current of CPU in HT Hyper Threading Technology Bass Motherboard . CPU is secure when the CPU Over temperature , high volt/low volt the system is auto shutdown . Motherboard which not use the HT Technology in which pin are leave blank .

In HT base motherboard on placing CPU HT technology and placing HT technology normal CPU . Then it is work as normal .

NOTE : thermal diode is used in HT CPU . Main operation of this section to sense the temperature and provided the temperature sense signal to I/O controller IC . By which during the over temperature , I/O controller IC auto shutdown the system . And termal diode not placed in normal CPU , which CPU damaged during over the heat .

· Pin details of Hardware monitoring interface section :

Pin no 94, 95,96, and 98 : These pins are analog volt sense pin of IC . At these pins – 12V, 12V , -5V and 3.3V supply is provided to SMPS and sense by input.

Pin no 99,100: These pins are sense input pins of V core A , V core B . V core A pin sensing the of CPU core volt and display . And V core B sense the volt of system control IC and display .

Pin no 101: This reference voltage output pin of IC . Voltage , received at this pin is given to thermal diode .

Pin no 102, 103 and 104: These pins are temperature sensor 1 sensor 2sensor 3 input pins . By using these IC do the signal input of CPU socket temperature , Cpu slot temperature and system temperature .

Pin no.105: This pin is over temperature shutdown signal output . By using this pin system is auto shutdown during the CPU over temperature (70 to UP ) .

Pin no 106,107,108,109, and 110 : These pins are VID , to VID , Binary output pins of IC . By using these pins VID binary is provided to VRAM section .

Pin no 111,112 and 113 : These pins CPU fan speed control output pins of IC . By using these IC speed of CPU fan , system Fan , Cabinet Fan are controlled . By using these [pins speed of three fans are sense .

Pin no115,116 : These pins are FAN PWM (Pulse Width Modulation) control output pins of IC . By using these pins pulse width of Fan is controlled .

Pin no 118: This is the System Beep signal output pins of IC . By placing system speaker at this pin beep signal is obtained .

· Testing and fault finding of Hardware monitoring interface section:

This section is checked when the display are obtaining power supply is ON . But system is hanged on system post screen or restart again and again by giving message of overheats then this section is checked in following methods :

1. If system is hang at system post screen when the power supply is ON . Then press CMOS enter key before post screen is bring .

2. If the system is not hanged in the CMOS system then the thermal diode is damaged in motherboard or CPU . For this purpose we change the thermal diode shorts .

NOTE : Thermal diode is short in motherboard or CPU . And system is hanged and system is not hanged in CMOS setup . Then disable the monitoring utility in CMOS setup and system run correctly .

· Game Port , Joy Stick Port MIDI port :

Pin no . 119: This pin is serial data input of Midi Port 2 Bit 0 Data input section and this pin can be used as general purpose input output Port 2 Data input section.

Pin no 120: This pin is serial data output pin of midi port and this is the internal signal output pin .

Pin no .121: This pin is command input pin of Joystick A of switch 2 this is the input pin of port 1 bit?

Pin no.122: This pin is command input pin of Joystick switch 2 this is input pin of port 1 bit 6 .

Pin no 123: This is the input pin of Y position sense of Joystick A and this is the Port 1 bit 5 input pin .

Pin no 124: This is the input pin of Y position sense of Joystick B and this is Port 1 bit4 input pin.

Pin no 125: This is the input pin of X position sense of Joystick B and this is the Port 1 bit3 input pin

Pin no 126: This is the input pin of X position sense of Joystick A and this is Port 1 bit2 input pin .

Pin no 127: This is the input pin of command of switch 1 of Joystick B and this is the Port 1 bit1 input pin .

Pin no 128: This is the input pin of command of switch 1 of Joystick A and this is the Port 1 bit 0 input pin .

NOTE: Pin no. 121 to 128 are used for Bit , to Bit data input output .

· General purpose input /output port:

Pin no 64: This is the suspend Led output pin . At this pin during system suspend indication is obtained .

Pin no 69: This is Infrared Receive data output pin of IC . At this pin obtained information from Infrared diode is converted into digital information and obtained in the from of IR data .

Pin no70: This is the reset signal output pin of IC , Which is restarting the system .

Pin no 72: This is output pin of Power OK signal pin of IC , from which SMPS is continue ON .

Pin no 73: This is chipset suspend signal input pin of IC .

Pin no 87: This is Infrared Transfer signal output pin of IC . By using IR diode at this pin infrared signals are transfer . .

Pin no 88: This is Infrared receiving signal input pin of IC . By using Infrared transistor on this pin signals are obtained .

Pin no 89: This is Watch dog output time pin of IC . By using pin the system is send into the standby mode .

Pin no 90: This is the power LED Indicate output pin of IC . At this IC Power LED is placed .

Pin no 91: This is input output pin of Bit2 of Port-2 . At this pin serial clock pulse is given in the form input . This pin is also used in HR series.

Pin no 92: This is input output pin of Bit2 of Port-2 . At this pin is also used for HT supported motherboard.

Key board: 15,40,65,90. Pin no 15,40,65,90 is keyboard input output controller pin of IC.=842 AD .

· Power division sections:

Pin no 12,48,77 and 114: There pins are positive input supply pins of IC . 5V supply is given at these pins .

Pin no 61: This pin is positive input supply pins of IC of stand by selection . At this pin Stand by voltage (5V) (Violet wire ) is given from SMPS . This is ON during the power ON , system shut down .

Pin no 28: This pin is input supply pin of Host interface section made in IC . At this pin 3.3V supply is provided .

Pin no 29: This is positive input supply pin of analog section made in IC . At this pin 5V supply is provided .

Pin no 20,55,86 and 117 : These pins provided the negative supply to all the section of IC . These pins are grounded .

How to read Top marking of I/O controller:

· I/O controller:

SUPER i/o CONTROLLER OF VARRIOUS COMPANIES:

How to Read top Marking of I/O Controller

W: Winbond

W (Brand Name)-836 27 HF-AW

W- 83627-HF-AM

HF -Hypertheting

AF- Normal

AW –Award

PH- Phonix

AM- AMI

CHAPTER-10

BIOS

Bios are a basic input/output system, which is enabling all the hardware placed on the motherboard at the time of power on . As the power on BIOS program configuration are loaded in memory and test all the hardware, which is boot all the hardware during the boot of operating system . This BIOS programs are store in ROM IC and this IC is mounted on the main motherboard or sockets . This IC mainly PLCC 32 pin IC . BIOS programs are made by different companies in each computer , but general BIOS are AMI , AWARD , PHOENIX companies . These companies sell the BIOS source code to different – different credit .

BIOS gives the direction to the operating system that how you boot the computer , and where all hardware are loaded , what should be loaded , where the memory and CPU are placed and so more . A good comparison from of BIOS work as hypothalamus work for human .

Hypothalamus regularly maintains our temperature ., blood pressure , metabolism of fats , carbohydrates and leave of suger . Without this life is impossible . Like that without BIOS , computer is like a “paper wet” i.e this is workless .

Main Operation of this department is providing the POST signal to the CPU , during the power on .

From which CPU take out the working mode to all the hardware according to this signal . BIOS program are placed according to I/O controller on motherboard , that I/O controller supports this software . BIOS programs are made by different companies and this BIOS program are placed according to I/O controller on made by AMI,AWARD,PHONIX companies and BIOS software in original motherboard are made by this company . Like in Intel BIOS software are made by Intel . This bios software is stored in ROM IC , and then ROM IC is connected to motherboard and then run this software by CPU . ROM IC work as storage devices . This IC has the different-different capacity , like as 512MB , 1MB and 2MB……….. ..etc . manufacture is different –different of this IC like Win bond , Intel, Dell ,AT , MAX , TML …etc.

BIOS program are store in PROM, EPROM , EEPROM , Flash ROM . We known them BIOS chip .Its other name is – firmware hub, CMOS, ROM. We known them BIOS chip . Is other name is – firmware hub , COMS , ROM Chip , Flash ROM…Etc. if we say in general from than its name is BIOS chip is the famous name , which is known by all..

CMOS=(complementary mental-oxide semiconductor)

This is a semiconductor technique, which is use to generate low power and low temperature. It is work on the semiconductor which have two junction technique are used.

ROM IC is classified in following :

(1) PROM

(2) EPROM

(3) EEPORM

(4) Flash ROM .

(5) Firmware

1.P-ROM (Programmable read only memory) : This type of IC is known as once time read only memory . Once a write then we cannot erase program ,and this IC work as a IC fuse and antifuse . When program is done then byte the lock , which is known as circuits fuse and ROM is work as antifuse Operating voltage required for this IC is 12 to 21 V . This IC is identifying by its numbers

2. EPROM (Erasable Programmable read only memory) : In This type of IC 10 times erase and program . For erased of this type IC, we remove the sticker from IC and then below the sticker a glass window is made of ultraviolent tube , which is wavelength 235nM , on this tube light and keep 8 to 10 hours after that data is erased from IC. After erasing the data we place sticker again . After that programming is done by the universal programmable IC . Number of this IC is identifying by given table below and identification of this IC is performed by the Glass Window .

3. EPROM (Electric Erasable Programmable read only memory): This type of IC can be erased programmed 100 times. Erased and programmed time of this IC is 2 to 3 minute . This IC can be indentify by number .

4. FLASH ROM : This type of IC can be programmed and erased for life time . Programming and erased time of this IC is 2 to 3 seconds . This IC is Programmed and erased from a clock . In this IC data can be stored 120^otemperature for 100 years .

5. Firmware : This IC also in memory chip category . This work as ROM when electric is fail . This work as hardware and software . In Motherboard of inlet which uses the Flash ROM known as Firmware Hub .

Faults finding and testing of BIOS departments :

This department is checked when the reset signal are continue obtaining when the power supply on but display on motherboard , then we check the following types .

1. Fistly check the 3.3V at VDD of BIOS pin . If the 3.3V supply is not obtaining then check for open the VRAM/SMPS.

2. If the positive voltage is obtaining at the VDD pin of IC then check the clock signal and rest signal on the reset and clock pin of IC . If the reset and clock signal are not obtaining then check the clock department or CPU departments.

3. If the reset and clock signal are obtaining then check the data on the data pin IC DQ0 and DQ . If data are not obtaining at data pin then store BIOS file is damaged inside the IC . Program again in this .

4. If the time of programming, program fail message obtaining then ROM is damaged .

NOTE: if the new ROM IC is placed then access time must be common and Blank IC programmed by the programmer fist and placed them on the motherboard.

Enter C-MOS Setup Key

Company Enter C-MOS Setup Key

ALR Advanced Logic Research Inc. PC/PCI F2

ALR PC non/PCI CTRL+ALT+ESC

AMD BIOS F1

AMI BIOS DEL

Award BIOS CTRL+ALT+ESC

Award BIOS DEL

DTK BIOS ESC

Phoenix BIOS CTRL+ALT+ESC

Phoenix BIOS CTRL+ALT+S

Phoenix BIOS CTRL+ALT+INS

Computer Vendor Enter C-MOS Setup

Acer F1, F2, CTRL,+ALT+ESC

ARI CTRL+ALT+ESC, CTRL+ALT+DEL

AST CTRL+ALT+ESC, CTRL+ALT+DEL

Compaq 8700 F10

Comp USA DEL

Cybermax ESC

Dell BIOS web site search Links For Models not listed below

Dell 400 F3, F1

Dell 4400 F12

Dell Dimension F2 or DEL

Dell Inspiron F2

Dell Latitude Fn+F1(while booted)

Dell Latitude F2(on boot)

Dell Optiplex DEL

Dell Optiplex F2

Dell Precision F2

EMachine DEL

Gateway 200 1440 F1

Gateway 2000 Solo F2

HP(Hewlett-Packared) F1, F2(Laptop, ESC)

IBM F1

IBM E-pro Laptop F2

IBM PS/2 CTRL+ALT+INS after CTRL+ALT+DEL

IBM Thinkpad (newer) Windows:Programs-Thinkpad CFG

Intel Tangent DEL

Lenovo (formally IBM) Lenovo BIOS Access page

Micron F1, F2, or DEL

Packard Bell F1, F2, DEL

Seanix DEL

Sony VAIO F2

Sony VAIO F3

Tiger DEL

Toshiba ESC

Toshiba Protégé ESC

Toshiba Satellite 205 CDS F1

Toshiba Tecra F1 or ESC

Toshiba Notebook (newer models) 1. Turn on computer by Holding

Down power button while pressing the ESC key.

The machine will beep, then display

Check System, then press(F1) key.

2. Release ESC key

3. Press F1 Key.

INDEX

Laptop

1. CHAPTER-1

Laptop introduction, difference between laptop and desktop computer , history of laptop , Structure of laptop , various use of laptop , property of Ace Travel Mate 2400/3210/3220 ,de-assembling of Acer Travel Mate 2400/3210/3220

2. CHAPTER-2

Description of laptop block diagram , adapter branch , battery branch , DCIN and Detector branch Main system power supply branch , cpu branch , clock generator branch , system controller branch , DSP digital signal, LVDS (Low Voltage Differential signaling) , LCD TFT branch , CCFL , RAM , ICH , microcontroller branch , I/O controller branch , VHS , Super I/O controller branch , Audio driver and Amplifier branch , Keyboard branch , Mouse branch , IEEE 1394 , SCSI branch

3. CHAPTER-3

Laptop’s adapter branch , fault finding and testing of adapter , battery branch , description of IC’s used in battery , working of circuit , fault finding and testing of battery

4. CHAPTER-4

Description of circuit and testing of different parts of Acer Travel Mate 2400/3210/3220 Laptop .

5. CHAPTER-5

LCD pane , working of LCD , Passive matrix LCD , active matrix LCD , TFT , color filter ,TN+Film (twisted Nematic+Film) , IPS (IN-PLANE Switching ) , MVA/PVA (Multi0domin vertical alignment/patterned vertical alignment) , LCD Panel manufacturing process , Aspect ratio and display area , dot pitch or pixel size resolution area of liquid crystal display , guidance of handling LCD panel .

6. Fault finding of laptop (Color page)

CHAPTER-1

LAPTOP

INTRODUCATION:

Laptop computer is small, mobile personal computer. If we understand its literal meaning then it is so called because of it can be use at the top of our lap . So laptop computers are that computer that can be use even we put on our lap.

A laptop computer is also known as notebook computer. Generally its weight ranges from 1 to 3 kilograms. Followings are kind of notebook computer and its related category :-

· Size is less than A4 size paper and weight is approximately 1 kilogram are known as sub-notebook or sub-notebook computer .

· Notebook type computers having weight approximately 5 kilogram are known as DESKTOP notebooks.

· Those kind of notebook computers which much powerful and can be as useful as desktop computers , are known as computers used in place of desktop computers .

· Computer having size less than notebook computer but greater than palmtop computers are known as PDA, (personal digital assistance) .

Hence, Laptop computers are small in size, use with battery , light weighted and it is ideal for those kind of person who need to take computers from one place to another place . Like business related person who mostly do journey or university student who can use it easily in their bedroom , library , lecture hall or café . With one DVD player , laptop computers can also be use as portable entertainment system .

Laptop are generally used with battery but it can also be used as an adapter which uses mains electricity, charges battery also. Laptops are generally used with battery but it can also be used as an adapter which uses mains electricity , charges battery also . Laptops are generally able to do that works which are done by desktops .Through they are more costly than desktop but less power full . They are completely portable , use less power and cause fewer noises than desktops .

Parts used in a signal laptop are same as that of laptop and do same works as desktops , but its parts are design in such a way that they uses less power . Generally laptop uses liquid crystal display (LCD) as a display device and for memory it uses SO-DIM (small outline dim) module which are small in size in comparison with DIM used in desktop . For input to the laptop it uses one keyboard and a mouse as a pointing device . A same kind of mouse and a keyboard can also plug to laptops as peripheral device.

Difference between desktop and laptop

Generally desktop computers are come in vertical chassis , which is known as tower and it used at floor below the desk . A monitor ,a keyboard , a mouse and speakers are distinctively connected with tower .

Different from desktop computer ,laptop computer has inbuilt all the accessories like keyboard , mouse , speaker etc but can also be attached as a peripheral device . These accessories have likely same cost in both the laptop and desktop computer .

Big cases of a desktop computer have a motherboard , video card , hard disk , and many other components are attached . In this case monitor keyboard and other peripheral devices are attached by either wire or wireless connection . This computer case is May b vertical or horizontal ; this has sufficient space to connect card , cables and other circulations.

A laptop is light weighted and small in size as compared with a desktop . Is display screen is attached by one part of laptop . Keyboard and touchpad are also part of laptop . Keyboard and touchpad are also a part of laptop . Laptop has not more space for air circulation as compared to the desktop . All other components are attached in laptop end to end , so that its width is less than a desktop

Aon the basis of design and portability of a laptop , components are attached as

· They are attached on the basis of fixed size .

· On the basis of less power consumption .

· Components will produce less heat as compared to desktop .

Components attached to laptop on the basis of above description are costlier than a desktop And hence increases the price of a laptop.

History of Laptop

Before the use of a laptop there are various thoughts emerges on the size of laptop . Fist of all , in start of 1970 mainly a Xerox park named computer by the book ‘alien ki Dayan ‘ was popular OSBORNE -1 was first laptop which introduce for the business purpose in 1981 . This computer works on CP/M operating system . This computer is more big in size and heavy as compared with present laptop , which uses a CRT monitor . Firstly, by this computer, data can be transported one place to other as data can be transported one place to other as business propose. In 1976 through Xerox note taker “Xerox perk” named ten copies of computers are manufactures , which can be transported from one place to other like monitor etc . Size of Osborn computer is similar to a sewing machine and to secure it from vibration it can be transported with the help of plane to other . This Osborn computer can not be operated with the help of battery. It requires man’s power to operate . In 1983 first IBM compatible portable computer is manufactured to the market . This computer also works similar as first similar shape of IBM PC .

In 1982 there is a trend of GRID compass 1101 named computer , which is designed by bill merged in 1979 , is the first real laptop computer . In this Laptop computer first time attached Keyboard and flat screen with the laptop internally and its display is of 320 x 200 pixels plasma display . In it 384 K bubble memory is used . This laptop is not IBM compatible and its used only for some special specific purpose . Mostly use of this computer in the space shuttle , sending in the year of 1980 though the US military . After this , this computer also made “ tendy “ named laptop . At that time many other popular laptops were PC500(in 1986) , gavalin (1984) etc . Gavalin was the first totally computer coming in the category of laptop computer in the world. In this computer in first time used the touch pad as pointing device . LCD display is used in the both , sharp and Gavalin computers and these both computers are capable of joining optional printer with then . Both of them are partially IBM compatible computers. And used their own operating system.

Earlier most selling closyre , cyotronic -85 laptop computers was born in 1983 . This computer get slow speed of selling but other companies started manufacturing after taking licenses . According to this design tendy corporation and NEC polyvity M-10 and NEC PC 8201 named computers are lunched in market. Radio Shack Company lunched same design by name TRS80 and model -100 in the market . All these computers are capable of working on AA – batteries . In its internal program has basic internally, text editor and terminal program was manufactured by Microsoft , which was written by bill gates . In this computer8 x 40 character LCD screen is used. Due to attached the Modem internally this computer was known as highly portable communication terminal. This laptop was more popular in between the journalist because of its features like portability , long life battery , lower price , and more reliability . Its weight is less than 2 kilogram and its size was 30x21.5 x 4.5 centimeters . In it minimum 8 KB and maximum 24 KB memory was used with 3 MHZ processor .

Firstly in 1986 IBM compatible profession computers are used . In this category , Toshiba T1000 and Toshiba T1200 lunched in the market in 1987 . Due to less in the weight and smaller in size Toshiba Machines are easily transported from one place to another . Its operating system is stored in ROM . These are floppy based DOS machines in which led acid batteries are used . In these computers at present feature of resume is included which means computer can be paused in between any work . There is no need for reset in each time as in earlier computer does .

In 1988 computer designed by caliv syncliater called Cambridge Z – 88 was the first computer of this category . This computer is A4 size and it is capable of working of basic spread sheet , word processing , communication program on stand batteries . This computer was first real from of presently present laptops computers . In this category includes TRS-80, 100 etc . model was also generate , which are far generation of PDA’s used presently .

Till the end of 1980 laptop computers are become popular between professional persons . NEC ultra light comes middle of 1989 in the market and it was the first notebook computer of the world , in which hard dis drive instead of floppy disk . It weight is about 2kg and 2 MB ROM drive was used . COMPAQ LET category was the first notebook computer comes with the standard drives , which is lunched in the end of 1989 in the market . In this computer first time used the hard disk drive with standard resolution screen .

Macintosh manufactured first apple computer was designed in 1989 , in which externally connecting LCD screen was used . In this Mac portable computer active matrix was used with long life battery backup , but it is very big in the size and due to heavy it is not more useful in the running market . Next computers of Apple power book category lunched in the market in the year of 1991.. device like track ball are combined implicitly .

This year IBM has lunched think –pad series in the market and in this category first time along with 256 color display Ethernet card for networking and real touch pad is also consists. As the technique is developing, price of laptop is decreased and popularity and its use is increased . In these development years laptop design is changed in such a manner that its importance is now similar to the desktop computers.

The changes are following amongst all:

Composite battery technique:

Under this technique heavy led acid batteries are converted into Nickle metal hydrate (NI-MH) batteries and Lithium ion or Lithium polymer battery technique .

Power Savings Processors

In 1991 only 80286 processors was used in laptops because 80389 processors are using excessive power consumption . For low power consumption in the processor of Laptop category 80389 SX processor was designed , by which faster speed could get in 386in comparison of 286 . After this all the processors used in laptop are designed according to the requirement of techniques used in laptops .

Power Saving Processors :

In 1991only 80286 processors was used in laptops because 80386 processors are using excessive power consumption . For low power consumption in the processors used in laptops are designed according to the requirement of techniques used in laptops .

Developed liquid crystal display design

This technique is used mostly in the active matrix display and more color capacity screen . Earlier laptop screens are in passive matrix which is black and white or gray scale from . This LCD is slow in speed displaying pictures and along with it shows heavy shades pictures . Few laptops are using sharp monochrome screen as plasma display but they consumes too much power . Because of technical development size of display , Sharpness , more display resolution etc features sre gathered in today’s structure .

Development hard disk technique

Only floppy disk drive is used in Earlier Laptops . As there is low capacity , thin and more resistance to jerks low power hard disk is avaible , manufacture of laptops stated using these to store their data and to carry data from one place to another .

Developed Inter Connectivity

IBM PC compatible laptops are used to carry outside home and plays important role as in internal modem and serial/parallel ports along with ether networking will used from 1988. In this categories in 1999 on the basis of USB PCMCIA and WIFI laptops are using peripherals same as like desktops .

Structure of laptop :

Structure of laptop is done on the basis of following points:

Microprocessor

Ton control computer microprocessor or CPU works with operating system . This is necessary part of brain to the computer. Microprocessor have internal instruction set which is stored in memory and when it needed to work can access through the memory . Microprocessor can find instructions from key board and other devices like mouse , touch pad, track ball , track stick according to our choice . This can store and receive data through various storage devices – hard drive , floppy drive , zip drive CD/DVD drive etc . It displays on screen of monitor (LCD display , Cathode Ray monitor ) . This can send data through various input/output port to printer , modems , networks and wireless networks . This microprocessor given the through the AC power and Battery .

CPU of laptop generates less heat is comparison to CPU to desktop . A CPU of laptop can use different techniques of cooling , which are as flows :-

- To run CPU in low voltage and slow speed :- It is run on low voltage and clock speed . By this generated heat will be less and less power consumption but the speed of processor is reduced . When there is power plug – in of laptop then it is mostly work on a high voltage and clock speed & when these are used on battery then it is work on lower setting .

- Attach the Microprocessor on the motherboard without using the pins : It is mounted on the motherboard without using the pins . In desktop PC’_s, pins and sockets occupies more space . Some motherboard processors are attached to motherboard without using sockets . In the others micro FCBGA (flip clip ball grid assay)is used , where balls are used , where balls are used in place of pins . Space is utilized with this design. But in this situation processor can not br removed or changed for up gradation .

- Sleep or slow down mode : In it there is slip or a slow down mode . When computer is not in use or there is no need for processor to run in fast speed then computer and operation system work together to make the slow speed of CPU .

In few laptops desktop CPU’s are used which is set to run on lower clock speed , whereas it makes improvement in work capacity, this laptop works better but reduces the battery life .

To reduce heat from CPU in laptops we use small heat sinks, heat pipes . In few higher laptop models this heat is reduced with the help of coolant which is kept in channels through the pipes . Mostly laptop CPU’s are built on the side of main unit , so that heat easily removes through fans and does not toches other parts and do not warm them .

Memory

A RAM whether it is connected inside the desktop PC or in the notebook computer , plays an important role for receives data or instructions from the program of hard disk and gives to the CPU . How much this chip will perform , that CPU gives better result according to its performance . By using this , speed of CPU as locomotive stream train because speed of bullet train .

There are four types of RAM in notebook computers:

1. SDRAM (synchronous dynamic RAM)

2. DDR SD RAM (double data rate SD RAM)

3. DDR2 SD RAM

4. DDR3 SD RAM

This type of RAM is not used as in comparison of DDR SD RAM . At present time DDR SD RAM is used as a standard desfults RAM . it is also available in DDR RAM DDR2 SD RAM from. DDR2 (double data rate 2) memory is next generation type of memory which makes processing and sis capable of 2 cycle per rate to send data to CPU , so that the speed of processing and capacity will be increased . DDR2 memory is used with advanced note book models like centrino etc . in comparison with DDR RAM bandwidth if DDR2 SD RAM is increased up to 60% .

In all types of computers memory is mainly in good condition . Earlier time laptops consist of minimum 16 MB memory , bit today memory is extend from 512 MB to2 GB . At present time maximum limit of memory in computers is up to 4 GB . But in some cheap laptops this maximum capacity is up to 1 GB only. A slow capacity processor can be used by increasing memory size .Few laptops are using cache memory within CPU or near CPU , to increase the speed of data exchange between them . In few laptops big buses are used in processor mother board or memory to increase speed . Memory modules are of small size used in laptops so that the size of laptops can be kept small .

At present mostly notebooks are using maximum limit of RAM up to 2GB but in some cheap models maximum limit is 1 GB . A laptop can decrease memory by decreasing few functions , these functions are from slow processors . Few laptops have cache memory in CPU which transfers data modules are used .

Storage

A laptop can use two types of storage media- non removable storage media and removable storage media. If CPU in computers is brain of PC then hard drive will act as a heart of PC . It does pumping of data for the remaining part of system and make PC to storage data for a long period 0f time . Hard disk is an important component of every computer . Hard disk while rotating records data in form of magnetic pulse from plate’s greater the speed of rotation of hard disk drive , greater the speed of transfer and receiving data . In mobile market main aim is of power consumption . Slow in speed of rotation of disk will increase battery life but it will decrease work capacity . Hard disk speed is calculated in resolution per minute (rpm)when we play game in notebook computer then we require high speed hard disk . Hard drive speed is normally 4200 rpm,5400rpm and 7200 rpm . For new devices storage capacity is increased every year bit the size is remain balanced (2.5 inches) in comparison . Biggest signal note book is of 120 GB amongst all . And minimum it is avaible of up to 6 GB. In laptop machines , RAID (redundant array of independent disk) configuration uses two hard disks also used to which gives maximum work capacity and back up facility . In advanced laptops (like second generation Centrino models 0 also uses one serial ATA (SATA) hard disk interface . This connection is like that in which industry SATA hard disk is moving and IDE (EIDE) adders are exchange laptop hard disk is small in comparison on comparison to desktop hard disk . In many laptops modular design is used in which many drive kits can be used in the same place .

These drives comes in three different names –

-Hot swappable : When drive is exchanged then computer can stay .

Warm swappable: When drive is changed computer can stay but related bus (the way , which drive use to send data to CPU) becomes inactive .

-Cold swappable : during swapping computer should be off .

Removable storage

CD/DVD

Today a CD burner/DVD-ROM competitive drive is used in every priced laptop as a standard unit. This can only happened in old models where CD-Rom is not fixed in the notebook . Because of this USB flash drive and integrated floppy disk drives popularity becomes down .But this is normally available in from of internal and external USB option .Maximum mid –to-high end laptops are using DVD players , so that we can use DVD and CD .

Media card readers

In many laptops built in media cards are available , which is used in various uses like –image is found with the help of camera in notebook . This can support secure digital (SD) memory stick, multimedia card , smart media and micro drive etc.

External hard disks

For a big removable and transportable storage requirement a right way is external hard disk. . You can connect PC to USB , fire-wire or one micro hard disk or PC card hard disk (like Toshiba manufactured).

Digital Signal Graphics Processing (DSP)

A digital signal graphics processing is also a microprocessor, which handles necessary calculation for 3-D graphics , which is made by motherboard or made by laptop special design of small graphic card in DSP . Manufacture of DSP are ATI mobility , v vidia , SIS, INTEL companies Laptop shares memory between CPU and DSP so that to reduce size and power consumption .

Display

In world of laptop computers it is display window and is known as primary interface . At present all features of laptops are received on Liquid Crystal Display (LCD) , based on Thin Film Transistor (TFT), which gives more advantage than cathode ray tube (CRT) like no rough text is received and no flickering is received etc. It means that it can be help to reduces the eye strain. In LCD each pixel is made independently . It means the these can be generate more sharp text in comparison of CRT , but when you want to display the graphics , then there can be problem due to high contrast text at low resolution becomes very difficult . This is also means that in CRT , graphics & text can be mixed and execute very sharply .

Maximum range of screen size is from 7 inches to 17 inches in laptops. At present time 15 inches is common in laptops , which is quite similar to 15.4 inches wide screen . TFT LCD display , CCFL tube is used for generating the display in Laptop screen. This display can be of black and white (16 grey scale) or color (5536 colors) passive matrix , key active , reflexive or backlit . Active matrix display provides sharper images on the screen and easy to read and backlit is better for low level lighting situations .

Sound

Chip used in laptop computers for sound is of normal quality . Speakers , used in the laptop for sound is also of small in size . This is the reason that quality of sound in laptops computer are not considered as important but as the time is passing slowly- slowly in comparison to old laptops sound quality is regularly increasing day by day . Intel company in Centrino platform computers under high definition audio DTS , THX and DOLBY technique has made 8 channels 192 KHz frequency 32 bit sound quality in laptops . But because of less space in laptops sound card and high quality big speaker can not be used , so high quality sound is not possible . For receiving Gaming and high quality sound , external sound controllers are used , which are connected with laptop through USB and fire wire port .

Use interface

In Laptop computers user interface is also divided into two parts-Input and Output.

Input

Like in any other computers , user is also needs of input for interchanging the information in the laptop . Main base of Input in the laptop computers is also the keyboard as in the desktop , but this keyboard is not a separate device it is inbuilt in the laptops .In many laptops computers , mouse can be connected externally through the USB or PS/2 connector . Where as in many laptops have touch pad or track point is made in place of mouse with keyboard . These touch pads are of different sizes but the main principal of working is same . There are two layers of material in touch pad from which one layer is response for working the horizontal movement and second layer is response for working the vertical movement . For this work different techniques are used like-wire sensor grid , semi conductive gel , electrodes etc . In all these techniques used finger movement on track pad is translated as mouse movement . Buttons can be clicked and documents can be clicked by rotations .A normal option is of track point device usd in place of Touch pad . These are made firstly on the IBM Laptops . These track points are made by load cells and placed on G, B and H keys of keyboard . Negative charge system is used for providing the real facility for cursor movement of using the track pointer , By using this system track point advantage becomes easier to use similar like a mouse. Track point’s acts as pressure of finger and convert it into direction by sensing and gives it to cursor movement, as a result by which in comparison to touch pad point gives the faster response .

Output

There is a need to connect the external output devices to Laptop/Notebook computers. In ancient Laptop computers PS/2 and Serial Legacy ports is used for this work . But at present its use is obsolete. Because today to connect the keyboard and mouse USB 2.0 and fire wire connection is connected. This Fire wire connection is capable of connecting the peripheral devices like camera on 400 MB PS. In every laptops 3 USB 2.0 ports are found but in past there are only 2 USB 101 ports are found in the Laptops . USB 2.0 ports are capable of working on 480nMBPS data transfer speed . One VGA port is also connected for connecting a monitor externally with the notebook computers. To increase its work capacity new hardware’s are connected in the laptops by using PC cards and PCI slots . With the help of PC cards , connecting the cards for using the sound card & extra ports . New Series of PC cards of small in size & fast speed areknown as express cards in the present time . In 2004 PCMCIA (personal computer memory card international association) establishes standards are used in industry which results at present PC cards are smaller in size and are used in equal from .

The way user treats computer without e-mail and internet surfing useless , in the same way it is very essential there is to be need of network communication in the laptop computer . Four methods are used for connecting the computer with network :

Wired

At present all the laptops are available with 56 Kbps modem (RJ-11) and 10/100 MBPS Ethernet (RJ-45) . Some professional laptop computers are used with 10/100/1000 GB Ethernet for special use .

Infrared

At present few laptop computers are also supports the infrared port . Today this infrared port is used for professional and engineering purpose . Its one normal use is to connect the mobile phone with Laptop Computers .

Blue-tooth

On the base of this technique , different types of other devices like : Mobile phone , Printer , handset & PDAs are connected on the small size wireless networking in the Laptop.

WI-FI

At present times WI-FI technique is using wireless networking technology is increasing at a faster growth . On this technique at particular fixed public access point with wireless network we can connect laptops and computer . Normally WI-FI modules consists of 802.11 A and G standards .

Docking Station

Today many professionals are used the laptop increasingly . By the use of this they can make their office portable but small screen and small key board makes it un-comfortable to use .

For solving this problem many people carry traditional keyboard, mouse and monitors with Laptop computer for long distance work . For this work we use docking station of laptop as shown in figure . .

Port Replicators

A port replicator is such type of device , connecting with the Laptop computers by which some connections are available for connectivity of desktop can be get in a Laptop , by which a user can use the standard devices , used in the desktop computer on her Laptop . A port replicators is shown is figure.

Power supply

Laptop and Desktop both the computers are work on the electricity . In both the computers a small battery is used for running the real time clock & CMOS RAM . Due to portable in the Laptop ,it is run by connecting the other batteries . These batteries are charged with Mains AC with the help of AC Adaptor . These batteries are used as backup power in the Laptop & these are mainly of three types:-

Nickle-Cadmium(Ni-CAD)

This is the first type of battery used in the Laptops. This type of battery is used in the old type of Laptop Computers . But in the few laptop computers today it is also using . After full charging it can be used up to 2 hours. This reduces time according to the memory effect . Due to the gas bubbles coming in the available cells reduce the charging period , by which total backup time period of battery is reduces. It is vary essential to discharge the battery totally at the time of each cell charge for solving this problem. These types of battery have danger of explosion in case of over charging.

Nickle Metal Hydride (NiMH)

Medium series of Lithium-ion Batteries & Ni-CD is known as Ni-MH battery . Life time of these batteries are vary small similar like the Ni-Cd batteries . These batteries are also effected with the memory effect. This memory effect is less in the Ni-MH batteries in comparison of Ni-CD batteries .

Li-ion battery

Li-ion battery are used as an standard in new laptops and computers . They are less in weight and works for a long period. They are not affected by memory effect and can be randomly charged . Also they are not having over heat and over charge problem . These are vary thin in comparison to other battery which is used to give support in small laptops. Li-ion battery can be charged up to 35000 to 4500 times in its life . Many laptops sets 5 hour of Li-ion battery back up but this calculation is also based on computer battery. Mostly battery consumption is done by hard disk drive , any other disk drive , LCD display in many laptops models battery consumption can be reduced by power management software to increase the life of battery . Also when battery becomes low then power consumption can be reduced.

Different uses of laptop

Laptop is complete computer which can perform all the work equally as a desktop can do. For example you can do the programming on it , word processing , spread sheet , data base , accounting and multimedia presentation can be mead on it . In reality many people are using laptop computer as a signal machine in their offices .

Laptop portability provides portability features to do as many works , which can not be done by desktop computers . For example you can write a sales proposal during a flight . Article and business projection can be made Or like the same other works can be produce during the bus or train travelling . We can categorize uses of laptop on following manner .

· Education

Laptop can be used to solve many problems of both students and teachers in the collages and university . For the teachers Laptop is very useful in many fields

· Projection

In a collage where combined lecture are given in one classroom , then many professors are this work by using laptop with the help of audio visual equipments to present slides and lecture notes .In today’s advancing technology laptops are also used in middle and high school teachers during the classes .

· Note taking

Students can use laptops computers to make notes during classes and lectures. Normally this technique is used in collage rather than in schools.

For this work special software known as hearing interpreter is used in the Laptops. in other way if any students have injury in his hand can use this software to download noted of lecture instead of writing .

· Laboratory

Experiments done in the laboratory by students of science at both school and college level can be stored in laptops so that data can be carried to any field as . These laptops can be associate with different probes and can be used to calculate temperature and humidity . Environmental temperature can also be calculated by keeping it in that presence . Instead of laptop scientific calculator and PDA etc are also used for this type of work .

· Other uses

In other uses of laptop computers are mostly used of business works and for entertainment purpose:

· Entertainment

Normally CD ROM and DVD are attached to every laptop so that it can be use for listen music and watch movies from the CD or DVD. Imagine that you are traveling to a long distance by train. During the journey you can listen to your favorite song with favorite CD and also can do your work with it or if you are traveling by a plane the instead of movie in the plane you can see your favorite movie at your laptop.

· Law-enforcement

Police cars are having laptops on so that of any incident occurs then it can be used to write reports and thus reduces the chances of forgetting the incident and saved time can be uses for more patrolling . And also we can connect wireless connection to the police headquarter so that to record criminal record can be searched , registration of vehicle , outstanding warrants can be seen so that urgently actions can be taken in response of any condition .

· Space-science:

Because of portability of laptops space scientists can travel with it easy and can store related information with the help of telescope . In these telescopes CCD cameras can be used to record images and can be seen afterward when needed .

· Navigation:

When boat is traversing in ocean then we need accuracy to find the position where we are standing ? In a small boat there is a limitation of space. At such type of boats no charter room and tables are available . At this type of place of laptop computers are using GPS(global positioning system) device with the help of right software. This software id installed in laptop does not consume more space.

· Business

Many people are saying that laptop computers have made revolutions on business field. Seller during traveling through internet can send any information , make orders , with the help of laptop computers in any fair can collect all the information with multimedia projection . And also laptop can be used in many other fields of business.

Specification of Acer TravelMate 2400/3210/3220 Laptop

Plateform & Memory (Acer TravelMate 3210/3220)

Intel^®Centrino^™ Mobile Technology, featuring:

· Intel^®Pentium^® M Processor 730/740/750/760/770(2MB L2 cache , 1.60/1.73/1.86/2/2.13 GHz ,533 MHz FSB)

· Intel^® Pentium^® M Processor 725 (2MB L2 cache , 1.6GHz, 400 MHz FSB)

· Intel^®915GM/PM Express chipset

· Wireless solution : integrated Intel^®PRO/Wireless 220BG network connection(dual-band 802.11b/g) Wi-Fi^®CERTIFIED™ solution , supporting Acer Signal Up wireless technology

Acer TravelMate 2400

· Intel^®Pentium^® M Processor 725 (2MB L2 cache , 1.6GHz, 400 MHz FSB)

· Intel^®Pentium^® M Processor 350/360/370(1MB L2 cache . 1.30/1.40/1.50 GHz, 400MHz FSB)

· Intel^®910GML Express chipset

· Wireless solution : integrated Intel PRO/Wireless 220BG network connection (dual-band 802.11b/g) Wi-Fi CERTIFIED^TMSOLUTION , SUPPORTING Acer Signal Up wireless technology

· Intel^®915GM/PM (for TravelMate 3210)/ Intel^®910 GML (for TravelMate 24000+ Intel ICH6-M (Mobile Intel 82801FB)

· 256/512 MB of DDR2 400/533 MHz memory , upgradeable to 2 GB using two soDIMM modules (duel-channel support)

Display

· 14.1WXGA color TFT LCD , 1280 x 800 resolution ; 16:10 viewing ratio , supporting simultaneous multi-window viewing on duel displays via Acer GridVista 16.7 million colors

· Intel^®915GM/PM (TravelMate 3210)/ Intel^®910GML (TravelMate 2400) integrated 3D graphics , featuring Intel Graphics Media Accelerator 900 and up to 128 MB of VRAM , supporting Microsoft ^® DirectX^® 9.0 and dual independent display.

· ATI MOBILITY™ RADEON ™ X700 with 64 MB or higher of dedicated VRAM, supporting ATI POWERPLAY ™ 5.0. PCI Express™ Microsoft^®DirectX^®9.0 and Dual/View (TravelMate 3210 only)

· MPEG-2/DVD hardware-assisted capability

· S-video/TV-out (NTSC/PAL) support (TravelMate 3210 only)

Storage Sub System

· 40/60/80 GB ATA/100 hard disk drive

· Optical drive options :

↠DVD-Super Multi double layer (TravelMate 3210/TravelMate 3220)

↠DVD-Dual double layer (TravelMate 2400)

↠DVD/CD-RW combo

· 5-in 1 card reader (MS/MS PRO/MMC/SD/xD-Picture Card)

Input Devices

· Acer Fine Touch TM keyboard

· 84/85-key keyboard

· Touchpad with 4-way integrated scroll button

· Four easy-launch buttons

· Two front –access LED-buttons: WLAN and Bluetooth^®

Audio

· Audio system with two built-in-speakers

· MS-Sound compatible

Communication

· Modem: 56K ITU V.90/V.92modem with PTT approval; wake-on-ring ready

· LAN: 10/100 (TravelMate 2400) or gigabit Ethernet (TravelMate 3210/TravelMate 3200); wake-on ring ready

· WLAN: integrated 802.11b/g Wi-Fi^®CERTIFIED ^TM solution (TravelMate 2400) , or Intel^®PRO/Wireless 2200BG network connection (dual-band 802.11b/g) Wi-Fi^®CERTIFIED ^TM solution (TravelMate 3210/TravelMate 3220)

· Acer Signal Up wireless technology support

· WPAN: integrated Bluetooth^®

Input-Output Port

· Three USB 2.0 ports

· 5-in-1 card reader (MS/MS-PROM/MMC/SD/XD)

· PC Card slot (one Type II)

· IEEE 1394 port(TravelMate 3210/TravelMate 3220 only)

· Fast infrared (FIR) port (TravelMate 3210/TravelMate 3220 only)

· External display (VGA) port

· S-video/TV-out (NTSC /PAL) port (TravelMate 3210/TravelMate 3220 only)

· Headphones /speaker /line –out port

· Microphone/line-in jack

· Ethernet(RJ-45) port

· Modem(RJ-11) port

· DC-in jack for AC Adaptor

· Acer ezDock (TravelMate 32220 only)

View Detail of Ports & button of Acer TravelMate 2400/3210/3220 Laptop

1. Display screen

2. Power button

3. Launch keys

4. Micro-phone

5. Status indicators

6. Palm-rest

7. Click button (left , centre and right)

8. Touch pad

9. Key-board

Close front view

1. Speaker- out/line-out/head phone-jack

2 . Mike-in jack

3.Speaker

4. Blue tooth communication button/indicator

5.Wirless communication buton/indicator

6. Power indicator

7.Battery indicator

8. latch

Left view

1. External display port

2. s- Video/TV-out port.

3. Network jack

4. Modem jack

5. Two USB 2.0 port

6. IEEE 1394 port

7. PC card slot

8. 5-in -1 card reader.

9. Interface port .

10. PC card slot exit button.

Right view

1. Optical drive

2. LED indicators

3. Optical drive exit button

4. Emergency exit hole.

5. Ventilation slot

6. Security key-board

Rear view

1. Battery nay

2. Power jack.

3. USB 2.0 port

4. Acer ez Dock port

Bottom view

1. Battry bay

2. Battery lock

3. Cooling fan

4. Memory compartment

5. Hard disk bay

6. Battery release latch

7. Wireless LAN card compartment.

Indicators

1. Cups lock

2. Num lock.

3. Media activity

4. Blue tooth

5. Wire less LAN

6. Power

7. Battery

Easy launch button and toch pad

1. Left button

2. Touch pad

3. Scroll button

4. Right button

5. Mail(e-mail application)

6. Web browser (internet browser)

7. E-(Acer e- manager)

8. P( user programmable)

(1) Removal of battery pack of laptop.

I. For this first of all carefully put the laptop down from back side.

II. According to the instructions given in figure push the battery lock and take out the battery pack.

(2) .Removal of wireless LAN card.

I. For this take out the two screw of door cover of PCI slot and remove PCI slot door cover.

II. After this remove wire of antenna placed in wireless card.

III. Press lock of PCI slot on side of wireless card remove wireless card.

(3) .Removal of hard disk drive .

I. For this remove two screw of HDD cover

II. After this with the PVC latch in HDD pull back to disconnect HDD to the back side and carefully remove hard disk drive outside .

(4) .Removal of memory from laptop.

I. For this remove two screw of DIMM cover .

II. Remove DIMM cover and press lock of DIMM slot and remove battery .

(5) .Removal of CPU from laptop.

I. For this remove two screws placed above CPU thermal door .

II. Remove thermal door .

III. Remove four screws of stopping thermal module and heating plate.

IV. Disconnect cable of CPU fan .

V. Remove carefully thermal module.

VI. Release CPU luck by rotating CPU lock built on CPU socket with the help of flat head screw driver .

VII. Remove carefully CPU from CPU socket .

(6) .Removal of optical disk drive from laptop.

I. To remove these remove screws lock of optical disk drive shown in laptop .

II. Pull back optical disk drive and remove it with help of flat head screw driver.

(7) Removal of LCD module of laptop.

I. To remove LCD module firstly according to image given in picture of LCD module carefully remove middle cover by slowly pushing it toward downside .

II. Remove two screws on top of key – board .

III. Remove key – board while disconnecting cable of key –board .

IV. After this remove wire of antenna carefully and separate it from main unit.

V. Discount LCD cable from main –board .

VI. Remove screws which are holding LCD module as shown in figure below .

VII. Remove other two screws in the bottom as shown in figure.

VIII. After this carefully remove LCD module from main unit.

De-assembling of main unit

(1) .removal of upper and lower case assembly of main unit.

I. As shown in figure remove 6 screws of upper case.

II. Remove 9 screws from bottom of main unit.

(2) de-assembling of upper case assembly

I. Disconnect touch pad FFC from main board .

II. If blue –tooth has to be connected then disconnected blue tooth cable.

III. Remove blue tooth module from upper case .

IV. Separate blue tooth cable from blue tooth card .

V. Separate touch pad FFC from touch pad

VI. Remove 3 screws from touch pad board .

VII. Remove touch pad board

VIII. Remove four way buttons from upper case.

IX. Carefully separate touch pad support from upper case.

X. Separate touch pad from upper case .

XI. Separate FFC from touch pad .

Lower case assembly

I. As shown in figure remove four screws from lower case in main board .

II. As shown in figure remove one screw from bottom in lower case main board.

III. Disconnect connection of speaker .

IV. Now remove carefully main board (mother board) from lower case .

V. Remove modem cable from main board .

VI. Remove two screws from modem board .

VII. Separate modem board from main board .

VIII. Remove modem cable from modem board .

IX. To remove speaker from lower case remove screws from screw hold .

X. Remove speaker set from lower case .

De-assembling of LCD module.

1. Remove 4 screws of LCD module.

2. After this remove LCD bezel .

3. Separate LCD module from LCD bezel .

4. Remove screw of LCD inverter .

5. To remove inverter removes LCD cable and inverter cable .

6. To remove LCD panel remove two screws of LCD assembly. As shown in figure .

7. Separate LCD panel from LCD assembly.

8. Remove 4-4 screws of LCD left bracket and LCD right bracket .

9. Separate LCD cable from LCD panel .

CHAPTER-2

The explanation of block diagram of laptop is as follows-

(1)Adapter section

The main work of this section is to first convert the A.C supply , through A.C socket , into D.C through switching process and then to supply it on output circuit on 9.6-21 volt and 1.5-4 ampere. For this work this section has SM transformer , switching MOSFET , oscillator I.C , and output controller I.C. Every laptop has adapter of different volt and ampere configuration and the size of their D.C output socket is different too .

(2)Battery section

The main work of this section is to providing the D.C. supply during the main A.C fail , by which the laptop computer remains ON for a long duration without any interruption . Nickel cadmium (Ni0cd) , nickel metal hydride (Ni-mh), lithium ion (Li-ion) cell is used to make laptop computer battery section and battery is connected to laptop through SM_BUS interface. In laptop the battery used is of 9.8-14.8 volt and 2 to 4 ampere configuration .The laptop battery status is obtained through SMBC and SMBD pins .

(3)DCIN & Detector section

The main work of this section is controlling the supply received from Adaptor & send this supply to Battery charging section , Main System Power supply section , CPU Core Power supply Section. This section is controlled through SHUT, Program Signal from embedded controller. This section is made by using different circuits in the different Laptop computers. P-Channel Power Mosfet is used in this section .

(4)Main system power supply section

The main work of this section is like ATX SMPS . This section becomes ON after getting signal through power circuit section and provides 3v , 5v liner output , 3v , 5v/4ampere switching output .Supply obtained through this section is given to every section of motherboard . This section uses MAX1999 chip . This section is controlled through MAINPWON signal .

(5)CPU CORE SUPPLY section

The main work of this section is to provide the CPU core voltage to the CPU after switching from high frequency through the T-Gate, B-Gat , received supply from DCIN & Detector Section. For this work ,in this section T-Gate, B-Gate , N-channel , power MOSFET, O/P controller IC oscillator .

(6)CPU section

The main work of this section is , supply received from CPU Core power supply stage , Clock Pulse received from Clock Generator, calculating the information received from system controller resetting through reset signal received from North Bridge given to the calculate data system controller . This section is made by using the Centrino CPU or Mobile in the Laptop Computer . In the Laptop Computer CPU Card Base, CPU Socket Base are two type .

(a)CPU card base- In CPU, Processor, System Control , Clock Generator , Temperature Sensor are made on a signal card and it can’t be upgraded because the same CPU is used in it.

(b)CPU socket base-In this type of laptop, the CPU is fitted in socket like desktop and FSB is updated according to the Processing Speed Supporting.

(7) Clock Generator section

The main work of this section is generate the clock pulse with the help of generator chip and crystal 14.31 MHz and to give it to CPU and other laptop sections. Different companies like ICS, IDT, Winbond Max are used in this section .

(8) System Controller Section

The main work of this section is to locate the data obtained through ICH or DSP to CPU and calculated data received from CPU to locate ICH,DSP. CPU card is used in P-I to P-III laptop computer. In this card system controller I.C and processor are used. In P-IV laptop using CPU socket place the CPU on motherboard. In which Laptop CPU card in that Laptop second CPU of the same model is used otherwise the card will not work.

(9)DSP digital signal processor section

The main work of this section is display the data obtained from system control. Data obtained through system control is converted in video format and video signal is convert in PAL, NTSC and then is to provide to analog RGB,DVI SIGNAL.

Signal is given to VGA port made in the laptop and DVI signal is send LVDS section through DVI cable . In different laptop different companies DSP is used . Flash RAM is used with DSP . In normal laptop Neo Magic , Intel , ATA , Mobility, S3….. like companies provided the required DSP.

In any laptop display driver is according to DSP .

(10)LVDS(Low Voltage Different Signaling)

The main work of this section is to sending the data in High Speed, given from GMCH, to LCD panel . For this LVDS format is used . LVDS section works like protocol . The main fact is that , transferring the data at the difference of low voltage transfer through the LVDS . Due to this there is no effect of radio frequency or any internal magnetic in the data. For LVDS transmitter and receiver section are being made . Presently these sections are made in the GMCH chip and timing controller section of LED panel . Value of the channel of LVDS is increasing according to the size of Panel . It means when size of LCD panel will increase then the number of LVDS channel will increase.

(11)LCD TFT section (Liquid Crystal Display, Thin Film Transistor)

The main work of this section is to show the display on the screen according to the LED on /off position which is got by the driving signal of LVDS. On whole panel any image is obtained in dot type. The number of these dots are according to the panel resolution . One dot is named by one pixel. One pixel contains three sub-pixel . These three sub-pixels are made by thin film transistor . If the resolution of any panel is 600x800x3 , then number of pixels in the panel is around 1440000.

(12)CCFL (Cold Cathode Fluorescent Lamp)

There main work of this section is to generate light in the back side of panel , due to which brighter image is obtained on the screen. For generating of light CCFL lamp, CCFL card is used . CCFL is of size 2.5” and more e.g-10”, 10.0”,11”11.1” .The on time life of this lamp is about 45000 hrs . Picture quality is increase according to the lumens size . Generally 150 to 200 Lumens are received, but in the good panel Lumen number are more .

(13)RAM (Random Access Memory)

In laptop computer RAM is according to the operating system. For e.g.-if any system is made for Win 98 then in this laptop 48 MB on-board RAM will be connected. But there are Micro SO-Dimm Slot in the Laptop for connecting the RAM separately . In each Laptop , number of pin in the Ram slot is equal to the slot size. But there is difference of FSB in it .

P1 laptop = 20 Mhz-66 Mhz

P2,P3 laptop = 66Mhz-133 Mhz

P4 laptop=133 Mhz>233,333,400,533……1075 Mhz

In laptop computer IBM , Kingston, Samsung ,Hynix Company RAM is used .

(14) ICH (Input Output Control HUB)

The main work of this section is to send the data obtained from input output slot and input output port to system control. And the calculated data obtained from system control is to be returned to the input output port and slot. By which, this data can save or send in any device. In IBM laptop FW82801 MB, ICH is used. The way ICH is being upgraded on motherboard, the no of output and input slots will be increase and also their data transfer speed.

(15)Micro controller section

The main work of this section is to control multifunction keyboard , mouse, I/O controlling , Super I/O controller, IRDA , Flash Bios , Volt-In Stage , Step Down section & Battery Section . Micro-controller Laptop also control all the circuit at ON and OFF position . Mainly every laptop this section is made by using H8/3437 micro-controller. This micro-controller comes of Hitachi company .

(16)I/O controller section

The main work of this section is to interchanging the data with ICH by controlling the PC Modem, PCMCIA Slot. Five type OF PC modem are placed on the PCI Modem Slot . And 16,32,64 bit PCMCIA card is placed at PCMICA Slot. Every laptop has 68 pin slot of PCMCIA. P-1 and P-2 it is 16 bit , in P-3 Laptop 32 bit and P-4-64 bit PCMCIA slot is placed. 16 Bit, 32 bit, 64 bit card can use in 64 bit Slot . But in 16 Bit Slot, 32 Bit, 64 bit card cannot be used .

(17)VHS (Video Horizontal Sync)

The main work of this section is to convert the analog video to digital, and then to store it in HDD. This section is used for download the video signal from video camera . This section is used in any laptop can be used. Today IEEE1394 port is used in place of this port.

(18)SUPER I/O Controller

The main work of this section to interchanging the data with ICH by controlling the parallel port, com port(serial port), floppy drive , IRDA, LPC Bus & Middi Port . For this super I/O controller chip is used in it.

(19)Audio Driver & Audio section

The main work of this section to convert the digital audio information to analog signal and amplifying it with amplifier I.C and providing it to the laptop speaker, by which sound is obtained in the laptop. In each Laptop this audio section made of different watt. Like:- 15w, 20w, 30w are some laptop in which audio driver chip is used to make this section.

(20)Key board section

In laptop 88 keys multifunction keyboard is used. But in the presently laptop multifunction+multimedia keyboard is used. Motifunction means to make use of any OS or without OS features during the laptop becomes ON position. Ex – brightness+,-,battery status CRT, LCD, Selection etc. These all features or function are used by pressing the Fn key. Laptop keyboard is Memron type keyboard. No chip is used in this keyboard. All the keys are joined to microcontroller by making key matrix through I.C hex inverter. By keyboard comes in the working conditions.

(21)Mouse section.

In laptop computer touch pad, Track ball mouse, is used. In Touch pad mouse body sensor, track ball mouse load cell and in ball mouse ball is used to make mouse section.

(22)IEEE 1394

The main work of this section is like the LAN card. In LAN card speed is about 10 to 100 mbps. But IEEE 1394 gives 800 mbps- 1GBPS transfer speed. Fiber optic cable is used to making the network. Its minimum length should be 1.5 meter. As well as the cable length will be increased, the Data Transfer speed will also be increased.

(23)SCSI section

In small computer System Interface Laptop computer SCSI PATA hard disk, SCSI SATA hard disk are used. This hard disk is small in size but its data transfer speed is like the normal Hard disk. SCSI hard disk is costlier than normal ones. SCSI hard disk size is about 2.5” and it comes in all capacity.

CHAPTER-3

LAPTOP ADAPTOR SECTION

In laptop computer 19v, 3.42 ampere adapter is used. This adapter is SM transformer base adapter . Block Diagram of this section is give below.

220V supply, received from AC Socket, is given to the Breeze rectifier through the Fuse(F1), NTC, Coil(L2), Load Resistance, (R1A1, R1B) 1W Frequency Controller Capacitor & Choke Coil. The 300v D.C supply obtained from positive and negative point of rectifier, is filter & store through capacitor C1(64µf400V) and given to the primary winding (A) of SM transformer & floating negative supply is given to the source of mosfet K1358 by the resistance R13(68Ω 1W). The Drain of MOSFET is joined to the B point of primary winding. Balancing Circuit is made at the primary winding of SM transformer through D1, L4, ZD1, ZD2. Switching signal is given at the Gate of MOSFET from UC3843 oscillator IC. Starting Positive supply is given is to this IC at pin no. 7 from the main AC the resistance (R2A, R2B, R2C, R2D, R2F, R2P) and the negative supply is given from bridge rectifier. Because of it the signals are oscillate from I.C & received at pin no 7. Pin no. 6 is joined to the gate of MOSFET. As the positive signal reaches at the gate of MOSFET it starts negative switching in primary winding. Thus it produces EMF in the primary winding, which is transfer into secondary and feedback winding. The supply received at feedback winding is given by (R₁₀120w) ,(R₁₀₎ 180w and positive supply is given to UC3843 I.C, and current sense signal are given to pin no.3 of IC by resistance R3, R4, R5, R13, by which gate drive could be set by sensing the switching current. Oscillator section, made internally in the IC is controlled at pin no.4 by C5, R5. Reference volt received at pin no. 8 of IC is given to Q2 IC 3.

The AC supply obtained from secondary coil of SM transformer is converted into DC supply by D1, D2 common cathode diode. This supply is given to output socket by coil after storing and filtering by capacitor 330MF/25V. For keeping the output supply in the load 22K x4, 1.5K x4, Q501(2X) NPN transfer is used. The ammeter of transistor Q501 is grounded and collector is connected to the load through a resistance and the base of the transistor is connected to the output controller IC HB00113/9603 Delta HIC.

For controlling and sensing the output current Delta HIC I.C, P721 (IC2), P721 (IC3), OPTO coupler Q505 are used. Negative supply obtained from SM transformer is given to pin no. 9 of the controller I.C. There is a shunt which is controller I.C. There is a shunt which is connected at the terminals of pin no 8 and pin no. 9 of I.C. because of it the supply obtained at pin no. 9 is now obtains at pin no. 9 is now obtains at pin no. 8. Now the negative supply obtained from pin no. 8 is given to output socket so that this I.C. senses the current from pin no.8 and 9 and out the signals from pin no. 1, which are given to pin no. 2 (cathode) of (IC2) OPTO coupler. Positive supply is given pin no. 1(Anode) by 1 KW, by which LED becomes ON and spread the light at the base of transistor. This transistor becomes ON with the light & flow the negative supply from pin no. 3 to pin no. 4. Pin no. 4 is connected to pin no. 1 (capacitor) of oscillator I.C. UC3843 thus this I.C increases the oscillate signals according to negative trigger. When the output volts become high then volts obtained at the base of Q505(2X) transistor by the ZD 501 ZENER diode. This transistor comes in on state because of high and supplies a negative flow from ammeter to collector, thus the I.C. 3 (P721) OPTO coupler becomes ON and make the transistor QA(2X) in the ON position. This flow the negative from ammeter to collector and provide the negative supply to pin no. 1 of IC by diode. Regular negative supply is obtained at pin no. 1. Oscillator section of IC make shut down. Keep the transistor QA continuously ON, NPN transistor QB (2T) is used, so that adaptor becomes shutdown.

ADAPTOR TESTING AND FAULT FINDING

We check this section at that time when the laptop computer is not running in AC mode & Power becomes ON but working properly in the battery mode than first of all check the 19V supply at output socket of the adaptor. If we are not getting 19V supply hear then we will check adaptor in the following ways:-

1. First of all check the +300V DC supply at the positive and negative terminals of CR1(D35B60). If it is not getting the DC supply then check 220V AC supply at rectifier’s AC point . If we are not getting the AC supply at AC point then check F1(fuse 1), NTC, L2(coil) for open.

2. If fuse is opening continuously then remove it and join a bulb of 220V/100W in the series. If the bulb is glowing full on switching power ON then check Breeze rectifier C1 (68MF/400V) capacitor K1358 & MOSFET for short.

3. If the bulb becomes ON once & OFF again then disconnect the bulb from the circuit & connect the Fuse & check the 300V supply at negative & positive point of breeze rectifier. If we are getting the supply and till now if the output is 0 then check the logic of 1.7V at the gate of MOSFET. If we are getting the logic then check the resistance joined at the source of MOSFET for open is resistance is OK then MOSFET is open, so change the MOSFET.

4. If we are not getting the signals at the gate of MOSFET then first of all check 12V supply at pin no. 7 of UC3843 I.C. if the supply is not coming then check R2A, R2B, R2C, R2D, R2F, R2P for open .

5. If the resistances are heating up, it means UC3843 I.C. is short. Change it.

6. If we are getting supply at VCC pin of I.C. then check 2.5V supply at volt reference pin no. 8 of I.C. If volts are not obtaining then I.C. is defective. Change it.

7. If we are getting the reference volts but not getting 1.7V logic at pin no. 7 then remove the shut down transistor QA(2X) connected at pin no. 1 of I.C, from the circuit if we will get the output volts on removing the transistor from the circuit then check the transistor QA, QB(2X,2T) joined in shut down section for sort.

8. If the transistor is alright then check output controller section joined at output. For this check high at pin no. 2 of opto coupler IC3(P721). If we are getting low at pin no. 2 then check Q505, ZD501 for short if the output volts are high then it means it is working properly.

9. If the output volts are high then check R11, R3, R4, R5 for open. If the resistance is alright then UC3843 I.C. is damaged.

10. If we are getting output volts very low then we will check (R13) 68Ω1W resistance joined at source of MOSFET for high value.

11. If laptop starts working with adaptor sometimes but not every time and laptop computer is already then change the current sensor I.C HB00113/9603 Delta HIC joined in output.

NOTE:- if HIC Delta I.C is defective and a new one is not available then remove the I.C. from the circuit. Sort the I.C. and Pin no. 8 and pin no. 9 of PCB mutually and check the base of Q501 load control transistor with the following circuit.

BATTERY SECTION

In the laptop computer the main work of battery is to keep on the laptop computer for a long time when the AC supply failed. In the battery of laptop we join Li-ion, Ni-cadmium, Ni-Methiem cell in series and parallel and adjust the value of current and voltage according to need. In battery charging discharging MOSFET, Volt or Current Sensor IC, SM Bus Interference IC, EEPROM are also used. The block diagram of this section is given further.

DESCRIPTION OF BATTERY SECTION

1. CELL

In the laptop’s battery Li-ion, Ni-Ca, Ni-MH cell are used. Li-ion cell are usually of 3.6V-9.7V and its current rating is maximum of 2 Ampere. Ni-Ca, Ni-MH cell 1.2V & any ampere current rating is (2 Amp., 5Amp). In the Li-ion battery the cell is connected in series and parallel but in Ni-Ca and Ni-MH batteries cell is connected only in series combination.

(i)Series: V=C1+C2+C3…………

I=Minimum Fix

(ii)Parallel: V=Maximum Fix

I=C1+C2+C3……..

(i) Exercises 1 (ii) Exercises

Note:

1. The volt should be same at the time when connection the cell in parallel combination Otherwise the cell with low voltage will always be in charging mode. And that cell will be damaged by overcharging.

2. If we will give the 0.7V more than its real charging voltage then the battery/cell will be charge.

3. To charge any battery we have to provide 10 times lesser current then the battery current.

Ex- we will charge 1v, battery 10 amp with 12.7 v, 1 amp.

(iii)Exercise (iv)Exercise Figure

(v) Exercise= Battery Brand Name=IBM

Battery Type=Li-ion

Battery Volt=10.8V

Battery Ampere=5 Amp.

No. of Cells=?

Per Cell volt and Ampere=?

Hardness of Cells=?

Differences between Li-ion and Ni-Ca/Ni-MH cells

1. These cells are of 3.6v-3.7v.	1. These cells are of 1.2 v.
2These cells can have current value 0.1 amp to 2 ampere.	2. These cells can have any current value.
3(i) Will damage on over charging, shot circuit and overheating(70⁰C). (ii) these cells can also dead.	3.(i) Will damage after blasting on overcharging, shot circuit and overheating (70⁰C). (ii)On short circuit the voltage becomes zero but we charge it again.
4These cells can be discharging and charged 4500 times.	4.These cells can be discharged and charged 2500 times
5.Cost=350 /-Rs.	5. .Cost=100 /-Rs.
6. These cells are used in all the laptops now days.	6. Not used quietly now a days.

Testing of Ni-Ca, NI-MH, Li-ion with Multimeter

S.No. Ω Battery voltage % Ranking

1. (0) to 150 Ω 3.6V, 3,7V, 1,2V 100% Excellent

2. 15W to 250 Ω 3.6V, 3.7V, 1.2V 90% Good

3. 250W to 250 Ω 3.6V, 3.7V, 1.2V 50 % Half

4. 350W to 500 Ω 3.6V, 3.7V, 1.2V 25% Poor

5. 500W to> (Above) 3.6V, 3.7V, 1.2V 0% Dead

NOTE: Any cell will be check with the multimeter according to the above table at the time of Discharge. If cell is showing negative continuty at the time of testing this cell is charge & volt will be obtain.

DESCRIPTION OF ICs USED IN BATTERY

1. IC BQ 2040 : IC BQ 2040 is a SM BUS Interface gasgadge IC. The interface, made within the SM BUS is used to keep the record of Battery charge, available in the battery pack in the connecting system. BQ2040 is able to monitor the capacity of the battery like Ni-Cd, NiHM, Li batteries and all batteries made on the basis of chemistry. System management BUS version 1.0 (SM BUS) protocol and smart battery data (SB DATA) etc commands are used by BQ2040. The charge control functions of SB data are also supported by this I.C. . On the basis of this it avails the battery charge status on the serial link, left power, left time and chemistry etc. By using the four segmented LED display it can directly show the battery charge. This display perform on the basis of 25% increment. On the basis of stored information in EEPROM in the outside part of ICBQ 2040 it is able to calculate self discharge time and temperature of the battery according to the mid situation between discharge and charge itself.

Three nickel cells can be operated directly at a time by BQ2040. For this by using a reference output and a outer transistor with a economic regulator circuit, VCC volts are provided according to configuration according to need of working BQ2040 the starting data can be program by using outer EEPROM.

DESCRIPTION OF PINS OF BQ2040

Pin no.1:VCC :- supply voltage input pin: 3 to 6.5 volts can be given to this pin.

Pin no.2:ESCL:- serial memory clock: This pin is connected with EEPROM IC in this circuit. The output obtained from this pin is used to data transfer between IC BQ2010 and the non volatile configuration memory situated outside.

Pin no.3:ESDA:- serial memory data and address: This pin is connected with EEPROM IC in this circuit this bidirectional pin is used to transfer the data and address both . And this transfer is in between the outer non volatile configuration memory and this IC BQ2040.

Pin no.4:LED-1:display segment output: this output is used to drive the external LED-1. And this pin is not used in this circuit.

Pin no.5:LED-2:display segment output: this output is used to drive the external LED-2. And this pin is not used in this circuit.

Pin no.6:LED-3:display segment output: this output is used to drive the external LED-3. And this pin is not used in this circuit.

Pin no.7:LED-4:display segment output: this output is used to drive the external LED-4. And this pin is not used in this circuit.

Pin no.8:VSS :negative voltage supply pin: this pin is grounded in the circuit and given a negative supply.

Pin no.9: sense resistor input : this pin is given a negative supply by the 100 K resistance are monitored in between SR and VSS pins on the basis of which changing and discharging process can be stopped. SR input is connected with sense resistance. Other end of this sense resistor is connected to the negative terminal of the battery. VSR<VSS indicates a discharge process while VSR>VSS indicates the charging process.

Pin no.10:DISP: display control input: this pin is used as high in on state and as low in off state this pin is not used in this circuit in the condition when DISP(BAR) is high it disables the LED display. DISP high help in keeping the LED display active on up and down during charging process. And DISP at time of low is able to keep the LED display on for seconds.

Pin no.11:SB: secondary battery input: this is an input pin of battery sense. In this circuit a positive supply is given to the cells by 1 MW resistance this pin monitor the peak voltage by the medium of high impedance resistor divider network peak voltage is also monitored on the basis of SBD resistor function voltage and as well as discharge voltage, last voltage(10.5V), and charging voltage parmeters can also be monitored.

Pin no.12: PSTAT: Protector input: this pin is not used in this circuit. By this pin we can find out the over voltage of lion protector circuit and the “charge suspend request” “can be send”.

Pin no. 13:SM BD: SM BUS DATA : this is an input/output data pin. In this circuit the battery is connected to micro controller H8/3437 with the help of this pin. This open drain transfers the bidirectional data address and data from BQ2040.

Pin no.14:SMBC : SM BUS CLOCK: this pin works as bidirectional pin and provides clock to data transfer from IC BQ2040.

Pin no.15:REF: Reference output for regulator : This pin is used to provided reference output to the micro regulator made on the basis of optionally fate.

Pin no.16:V OUT: supply out: This pin is used to supply power to the EEPROM configuration memory situated in outer section.

2. IC MM 1414C: It is a monolithic I.C, by which safety is provided to the Li-ion batteries. This MM1414C IC is also used as protection from over charge, over discharge, and over current to the Li-ion batteries. There are mainly two functions in this I.C. , “one is over current detection function” by which the problems during charging of outer FET switch can be solved by offing the IC. The other function is used to prevent the battery from over discharge. A battery is given volts for more than a definite time and that definite volt is used for discharge according to this function. When this work is done the IC should be in low consumption mode. This IC is used to short circuit the FET switch off at the time of over detection function and the time of over current flow.

Description of pins if IC MM1414C

Pin no.1: OV: Over charge detection output pin: This pin is used to control the gate of discharge MOSFET.

Pin no.2:N.C: Not connected.

Pin no.3:CS: Over current detection pin: This pin is not used in this circuit. This pin is used to monitor the similarity of the current. This work is done on the basis of difference of source of discharge control FET and drain by doing high the DCHG pin. This process is completed by lowering the current detection voltage and offing the discharge control FET after this the over current detection pin starts to come out from this pin and when the load becomes less, the over current is released this function is not used in o0ver charge mode.

Pin no.4:N.C.: Not connected.

Pin no.5:DCHG: discharge control FET pin: This pin used to control the gate of discharge MOSFET in the output section. At time of over discharge this pin becomes high and remain in low position in normal operation.

Pin no.6:N.C: Not connected.

Pin no.7:CDC: over discharge detection dead time setting pin: this pin is used to provided information about charging and discharging of SM interface IC. The dead time settings are done according to capacitor situated between CDC pin and the ground.

Pin no.8: COL: over current detection dead time setting pin: In this circuit this pin is used to ground a capacitor and for its dead time settings.

Pin no.9:cov:over charge direction time setting pin: this pin in use to ground the capacitor for dead time setting.

Pin no.10:Input ground pin: this is the input pin for negative supply and it grounded in a circuit.

Pin no.11:SEL:sel switch pin: this pin is not used in the circuit.

Pin no.12 & 13:these pins are not made.

Pin no.14:N.C.: Not connected

Pin no.15:V1:V1 high side voltage input pin of cell: this pin get connected on v1 point of cell.

Pin no.16:V2:V2 high side voltage cell & law side input pin of V1 cell: this pin connected to V2 point of cell.

Pin no.17:V3:V3 high side voltage of cell V2 low side input pin of cell: this pin get connected in inner point of the cell.

Pin no.18:V4:V4 high side voltage of cell & V3 low side input pin of cell: the pin is connected with V4 point of cell.

Pin no.19:N.C: not connected

Pin no.20:VCC:positive power supply input pin: this pin is connected through drain of resistance 511W of fate Q1PDT.

3.IC 24C 01A: it is 4k bit electrically erasable PROM this can be connected on a bus of 2 wires of 24C01 a devices. By this device can be done byte right operation of 1 MS with high speed. And which can be used higher temperature (40 degree to 125 degree C). In the from of special feature there is a facility of hardware protection in this IC to get correct upper block.

Pin no. 1,2,3:A0,A1,A2: chip address input: the level of these input pins compare with core responding bit of address slave. Behalf of compare of chip system get knowledge of it these input are necessary to connect with vss or vcc these three pins are connected in the circuit with vss pin.

Pin no.4:vss: negative supply input pin : these pins are ground in the circuit.

Pin no.5:SDA: serial address/data input/output pin: this pin is connected to pin no.3 of ICBQ2040 it is a bidirectional pin, which is used to get data from device and get done address into input/output it is an open drain terminal is necessary to pull up resistance of SDA bus form VCC. The used resistance R5(103w) in the circuit, which is used to connected like pull up resistor between pin no. 8 and VCC. SCL is reserve for indications of condition high start and stop.

Pin no.6:SCL: Serial clock: this pin is added to clock pin no.2 of IC BQ2040 the used of this input pin is to transferred data from device in the time of synchronization.

Pin no.7:WP: Right protection: it is necessary to connect this pin from VCC or VSS. This pi is grounded in the circuit. If it is connected with VCC than it’s upper memory block doesn’t execute during program operations. At this time read operations are possible when it connected with VSS than comman read-right operation are unable in whole memory area.

Pin no.8:VCC:+5v power supply pin: it is connected with pin no. 16 of ICDBQ2040 this battery pack can be describe by the following circuit diagram.

WORKING PROCESS OF CIRCUIT

Supply received from DCIN section is given to the Drain of Charging MOSFET. The source of MOSFET is connected to the source of discharging MOSFET. Positive supply is given to the gate of charging mosfet by connecting a resistance of 10K at Gate from Drain. To get the positive supply on the gate of MOSFET, mosfet becomes ON & flow the supply of charging volt from Drain to Source. Supply received from the Source is given to the Source of Discharging MOSFET. This supply is received at Drain through the Source to Drain Forward Bios Diode connected inside of Discharging MOSFET. The drain of the MOSFET is connected to the positive +B point of the cell inner part of discharging MOSFET from which cell charge gets start, when the battery is full charged, then by sensing the volt and current of cell by the V1 V2 V3 V4 pins of the IC MM1414C, then charging cut off signal high is out from pin no. 1.High received at pin no1 is given to the base of NPN transistor and Emitter of the transistor is ground. After receiving the high at the base of transistor, transistor flow negative supply from is grounded. After receiving the high at the base of transistor, transistor flow negative supply from E to C. Negative supply, obtained at C is received to the Gate of charging get stops.

MOSFET gate is received high logic by inserting10k resistance in drain to gate for giving battery supply which is receives at gate of discharging MOSFET at the time of, main AC fails by from which MOSFET gets on and flows source battery from drain. The supply on source has given of charging MOSFET source this supply MOSFET on drain placed to inside charging MOSFET by the forward bias diode it supplies volt in dept inside a laptop by the battery connector placed a fuse on drain which helps laptop to say ON when the main AC fails.

The signal out from CDC(charging Discharging Control) open pin no. 7 of MM1414CIC to get display status of battery status of battery to connect NPN transfer, N-channel MOSFET n this pin, SM bus interface IC gives analog battery status on slat Battery of pin no. 11 of BQ2040. This IC is IC Programmable analog to digital convert, LED Status IC. Same space has left on front panel battery status in IC. Internal part of IC converts analog signal to digital by analog to digital convertor dept received pin no. 11 and show out data status by the compare of IC data pin and stored program of IC to digital binary of the battery. This data display battery status to get read by the internal part micro controller of the laptop, which receives on battery status on the screen of laptop.

When the battery becomes low then first of all signal out to the battery over low from pin no. :7 of MM1414IC. It shows error signal display n the screen of the laptop by SM BUS Interface(your battery have over low please shut down your system in 15 seconds.)within the 15 seconds occurs of this error signal does not shutdown it than it shows in the form of discharging cut off signals high on the basis of NPN transistor placed on pin no. 5 as get high signals as flows negative supply transistor e to c. Received supply on C is given to MOSFET of gate. Thus, MOSFET gate off then the system gets shut down.

Testing of battery and fault finding

We will check this part till when battery of laptop is not giving backup on AC failure time. Battery is not detecting , Battery gets charge and discharge another second, This part will check as follows:

(1) If battery is not getting backup then go in C-MOS setup and will check battery status in battery options if in the battery status if getting a message “battery not installed” then we will replace SM Bus Interface IC BQ2040, EEP ROM in the battery.

(2) If there is a detection of the battery in C-MOS setup but then battery is not getting backup then separate battery from laptop we will make testing probe will get on by the help of adaption put on positive and negative supply point of battery. When you get on multimeter it shows 1 ampere then battery part is ok fault is in charging boost part and volt in part thus we will check volt on part.

(3) It is exists testing prob is not showing Multimeter ampere of supply point of +B negative point of the battery then we will spark battery from the box we will apply testing problem on +b negative supply point of series, parallel combination cell then we will check for open CH, DCH MOSFET if MOSFET is ok then MM1414Cis not good.

(4) If testing prob exists on +B negative point of the cell multimeter according to resistance table.

(5) If the time of charging a lot of heat occurs then we will check charging for MOSFET short.

(6) If the time of discharging after got an error massage auto shutting down then will check discharging MOSFET for short.

(7) If battery is receiving back up and getting status like 20% its hanged if will changes EEPROM(240CO1) IC.

Note: charging in battery discharging is not using thus the use of temperature sensor(thermal diode) in the battery will display message of full changed on time of discharge and backup will not be receive on the time of AC fails.

To be open of thermal diode battery will overcharging, overheat & will not be charging cut off. There can be a blast due to overheat of Ni-Ca, Ni-MH cell.

CHAPTER-4

Circuit Description & Testing of Different Section of Acer TravelMate 2400/3210/3220 Laptop

1. DCIN & detector part:

The most important work of this part is to get supply adaptor and battery control on it power selector. This part is made by use of DCJACK Battery connector, dual comparators IC LM393, transistor MOSFET diode.

(1)Adaptor DC Jack: supply out by coil PL1 and diode PD26 received by adaptor DC jack this is called by VIN these volt IN supply gives to the drain of power MOSFET PQ4(A04407) connected wit battery charging and power sector. DC Jack PL1 capacitor (PCN1) is having jack of 5 pins in which pi no. 1 supply positive and pin no. 2 supplys negative pin no 34 & 5 grounded a DC jack received supply from DC Jack to get filter there is a coil capacitor PC1(1000PF), pc2(100pf), PC3(1000PF), PC4(100PF) to stop reverse supply diode PD26(SBH1040)

(2) Battery conductors: there is a 7 pin connection for battery connection. Descriptions of pins are follows: pin no.1,6,7 is used o negative supply of the battery. Which pin no. 2 is negative pen of the battery of circuit. This pin of the data SM Bus to embedded controller which is connects of EC IC(u20) pin no. 164.

Pin no.3: this pin is the clock signal of SH Bus to EC. Which is connected to pin no. 163 of EC IC(u20)

Pin no. 4: this pin is the temperature sensing pin of the battery is sense. This pin is connected with pin no. 81 of EC IC(u20)

Pin no. 5: This pin is positive supply of battery, by which positive supply received from battery out through coil PL7, this is called by’ BATTt’ for battery discharges these supply discharging MOSFET PQ8(A04007) is given to drain & by the time of battery charging and on the time of battery charging and on the time of battery charging received positive supply coil(PL3) from charging MOSFET PQ7(A04407)& resistance PR44(0.02E) gets on this pin by it. Thus battery gets charge received positive supply on this pin is called “VmB:. To which gives over voltage protection circuit of battery.

For ESD Protection based on diode PD14, PD15 & PD16(BAS4004x3) from pin no. 2,3,4 of battery connector.

For sensing the DC supply received from adaptor and for ON the MOSFET, connected in the Battery charging & power selection stage, one comparator, of Dual Comparator IC (PUI) is used. For giving the fix volt to the inverting pin of comparator, “VIN” supply is convert in to “VS” volt through the Diode PD2(IN4148) & resistance PR11(33E). These VS volt is giving to positive supply pin of IC PU1(LM399). 3.3V fix supply made by linier regulator IC PU2 (G920AT24U) which is known by RTC volt REF.

The comparator’s pin is fixed by this RTCVREF supply. Charging volts are given to the battery through the RTCVREF supply resistance PR27(300E), PR26(300E) & diode D9(BAS40-40).

VIN supply receives at non inverting pin of comparator by resistance PR3(84.5K). When positive supply is received by the Adaptor. At that time high is receives at pin no. 3 of IC PU1, by which high is receive from pin no. 1 of IC PU1. These high are given at pin no. 26 of EC IC (U20) from the name of ACIN and these high signals from the name of PACIN are given to the gate of MOSFET PQ9(2N7002), PQ36(2N7002) which are connected in the battery charging and power selector stage, by which power of adaptor are selected.

At the time of receiving supply from Battery & AC adaptor, ‘MAINPWON’ signal are receive for making ON the +5VALWP&+3VALWP system power supply. For this Gate of other comparator PU1 IC is used. Inverting Pin of IC PU1 is fixed by RTCVREF supply. Positive supply received from the adaptor is given to non interring pin of PUI(LM393) IC by diodePD4(1N4148), resistance PRE9, PRE10, PRE12 and PRE15 (1Kx4) & MOSFET PQ35(TP0610K). This supply is known as ’B+’.

To get ON of MOSFET PQ35there is a fix transistor PQ33(DTC115EUA) when there is no supply from the adaptor, at that time transistor PQ34 is connected for making OFF the transistor PQ33 & MOSFET PQ3, by which signal is receive in the shape of AC OFF High from ECIC.

At the time battery supply, supply received from the source of discharging MOSFET(PQ6) is received in the from of B+ by supply coil PL2, which are given to non inverting pin of IC PU1. In the normal condition, high is receive at non inverting pin of IC PU1, by which high is received from pin no. 7 of ICPU1, which get in the from of ‘MAINPWON’ by diode PD5 these signals is given to +5VALWP and +3VALWP system power supply stage.

If the any reason doesn’t get the +5VALWP supply then transistor PQ3(DTC115EUA) is not becomes ON, by which MOSFET PQ2(2N7002) becomes ON and make low to non inverting pin of IC PU1, by which signal MAINPWON gets low and +5VALWP and +3VALWP gets off.

Testing of DCIN & Detector Stage:

This stage will be check at that time when battery charging and power selected part is not receiving the supply. For this we will check following components.

Check:- Adaptor DC jack PCN1, coil PL1, diode PD26, battery connector PJP11, coil PL7, IC PU1, MOSFET PQ1, regulator IC PU2, diode PD3, PD2 etc.

2. BATTERY CHARGING AND POWER SELECTION

Main work of this is to give the supply to circuit the adopter at the time of supply from the adopter and charging of battery. When supply not coming from the adopter, supply of battery has to give the circuit. For this work, we use Li-iON batter charging chip PU3 (MB3887), power the mosfet PQ4, PQ5, PQ6, and PQ7(A04407X4) transistor PQ37 (DTC115EUA) PQ38 (DTA144EUA) PQ8 (DTC115EUA) the mosfet PQ9 and PQ36 (2N7002x2).

Li-ION battery is a charging IC. Following are the description of the pins of Li-ION battery.

When power supply is becomes ON by the adopter at that time +19V(3.42A) supply is received at drain pin no.5,6,7 & 8 of power mosfet PQ4(A04407), which is received at the source of mosfet by diode connected internally in the MOSFET, which is known as P2 supply. But the current capacity of this supply is very low.

Source pin no. 1, 2 and 3 of PQ4 are connected with source pin no.1,2 and 3 of MOSFET PQ5. For making ON the both mosfets, mosfets PQ9 gets ON through DCIN & PACIN high signal received from Detector stage due to which we get a negative volt at gate of power PQ4 and PQ5 because these both the mosfets are of P channel, That’s why it is ON by negative supply and drain’s pin 5,6,7 and 8 of PQ5 (0.02E), which is known as +B supply. This B+ supply is given to various sections. B+ supply is out by coil PL2, which is known as ‘B++; supply.

When power supply becomes ON by battery, at that time then BTT+ supply is received pin no. 5,6,7 and 8 of drain of battery discharging mosfet PQ6 (A04407). This positive supply of the battery is received at the source of the mosfet by internal diode of mosfet. But the Current capacity of this supply is low. Thus, we need-ve supply to making ON the mosfet PQ6 because mosfet PQ6 is a P-channel the mosfet. VIN supply is given at the gate of mosfet PQ6 at the time of Adaptor supply by resistance PR33(47K), by which MOSFET becomes off and when supply is receiving OFF from the adaptor then we do not get positive volt at this pin. At that time from pin number 37 of EC IC (U20) we get AC off signal in high from, which is given to base of transistor PQ8 (DTC115EUA) through diode PD8(1SS355) by this transistor comes to ON state and out the negative voltage from the collector, that is given to the gate of MOSFET PQ6. When we get negative voltage at the gate of PQ6 then MOSFET passes the positive volt through drain to source, it is known as B++ supply , and which is given to different section of laptop.

Pin 1, 2 and 3 of MOSFET PQ7(A00407) source get B++ supply at the time of battery charging. Gate of mosfet PQ7 is connected with Fet Gate Drive pin no. 20 of Charging IC PU3. Both end of load resistance PR29 are connected with pin 1 & 24 of current detection amplifier 2 of IC PU3 for sensing the current of supply, received from adaptor whose current detection output signal is passed out from pin number 2 of PU3 which is supplied to pin number 84 of EC IC(U20). For working of PU3 (MB3887) IC the P3 supply is given to pin number 18 and P++ supply is given at pin no. 21 through the resistance PR34(0E). Negative supply is given to pin number 23 of IC PU3.

When PU3 IC get supply then reference voltage are out from pin number 6 of IC PU3. Through this reference volt non invert pin number 3 of error amplifier is fixed. And this reference volt is given to pin number 11 of IC.

Capacitor and resistance are ground from soft start pin number 22 of PU3 and resistance is ground from trigger pin number 17, by which this oscillator part works in the IC internally. But gate drive does not out the signal from pin number 20, util FST CHG high signal does not rece3ived at pin number 147 from pin no. 48 of EC IC(U20).

When FTCHG high signal received at pin no. 14 of IC PU3 then charging mosfet gate drive pulse are out from pin number 20 of IC, which are given to the gate of charging MOSFET PQ7, due to which MOSFET PQ7 becomes On and out the charging volt from gate to source, which are given to coil (PL3) and resistance PR44(0.02E). To rectify the charging volt diode PD24 and PD9 (SR530x2) are connected. To sense the charging volt current pin number 12 and 13 of IC PU3 are connected to both the ends of resistance PR44. This is current detection amplifier 1 pin of IC. The current ref is received at pin no. 9 in the from of high signal from number 101 of EC IC (U20).

Testing of parts of battery charging and power selection:-

This part is check when, laptop doesn’t on by adaptor or battery charging. To perform this we check following different parts.

Check:- MOSFET PQ4, PQ5, transistor PQ37, PQ38, MOSFET PQ36, PQ9, battery charging IC PU3(MB3887) MOSFET PQ7, PQ6, transistor PQ8, coil PL2, PL3 resistance PR29, PR44 etc.

3. +5VALWP & +3VALWP Main Power Supply Section

The main work of this section is to providing the supply to all the sections of motherboard by making +5VALWP and +3VALWP through B+ supply received from battery charging and power selector section. So, this supply is known as always supply. This section is made by using power MOSFET PQ11 and PQ10(A04912x2), main power supply controller IC PU5 (MAX1999EEI). Main power supply controller IC is 28 pin IC, its pin detail are as according to the given figure.

Circuit Description of +5VALWP & +3VALWP Main Power Supply Section

At pin number 20 of IC PU5 section +5VALWP and +3VALWP main power supply has given B+ supply by coil (PL4) and resistance PR56, PR171(4.7Ex2). And negative supply is given at pin number 23 of IC PU5.

When ICPU5 (MAX1999EI) get positive and negative supply then through +5V linear regulator out the +5 volt supply from pin number 18 of IC, which is given to VCC pin number 17 of IC and pin number 13 of frequency select through resistance PR59(47E).

After getting power supply to IC PU5, 2V reference is out from pin number 8 of IC, which has been given on SKIP pin through resistance PR65(0E), due to which IC works in ultrasonic mode. Reference volt from pin number 8 of IC PU5 is given to pin number 5 and 3 of current limit through devieder circuit.

Pin number 6 is shutdown control pin of PU5 IC. When there is low at this pin then IC will be in shutdown mode. So, for switching IC putting in the ON state, on this pin VS supply, received from the drain of MOSFET is given by diode PZD4 (RLZ5.1B), resistance PR 72(47K).

For regulating the +5 VALWP supply, PQ11 MOSFET is used. PQ11(A04912) MOSFET is a dual N-channel MOSFET, B+ supply is given at its pin number 1 and pin number 2 of drain 2 through coil (PL4) after getting supply from battery charging and power selector section. Pin number 4 of source 1 of MOSFET PQ11 is grounded, pin number 3 of gate of MOSFET is connected with pin number 19 of IC PU5. This is a output pin of ow side MOSFET drive of IC 5V gate drive pulse are not got until MAINPWON signal are not found at pin number 4 of IC in the from of high signal when there is high signal at pin number 4 of IC, then MOSFET drive pulse are out from pin number 16 and 19 of IC PU5, which are received to PQ11 of MOSFET, due to which regulated volt is out from pin number 5,6 and 7 of MOSFET PQ11, which are received in the from of +5VALWP supply by coil (PL4). To constant this supply, output supply is given to pin no. 9 of Feed Back 5V of IC PU5 through divider circuit. Capacitor PC48 () is being ground to filter the +5VALWP supply.

To regulate the +3VALWP supply MOSFET PQ 10(A04912) is dual N-channel MOSFET, pin number 1 and 2 of its drain 2 are supplied B+ supply through coil (PL4) by battery charging and power selector section, pin number 4 of source 1 of MOSFET PQ10 is ground. Pin no. 3 of gate 1 of MOSFET PQ10 has been connected with pin number 24 of IC PU5. It is output pin of low side 3V MOSFET drive of IC. Pin number 8 of gate 2 of MOSFET PQ 10 is connected with pin number 26 of IC PU5. This is a output pin of high side 3V MOSFET of IC, 3V gate drive pulse are not received until MAINPWON signal doesn’t received on pin number 3 of IC PU5. When there is high at pin number 3 of IC then MOSFET drive pulses are out from pin number 24 and 26 of IC PU5, which is received by MOSFET PQ10, due to which from pin number 5,6 and 7 of MOSFET PQ10 regulated +3VALWP is out, which is get in the form of _3VALWP supply through coil (PL5). To being constant this supply out5put supply is given to pin no. 7 of Feedback 3V of IC PU5 through the divider circuit.

Capacitor PC53(150uf) has been grounded for filter the +3VALWP supply.

When +4VALWP and +3 VALWP are correctly found then through pin number 2 of IC PU5 SPOK signal are out in the form of power good, which is given to the gate of MOSFET PQ39 then MOSFET is being in ON state and send negative supply to the gate of MOSFET PQ04.

B+ supply has given to source of MOSFET PQ 40(TP0610K), when negative supply received at gate of MOSFET PQ40 then from drain of MOSFET PQ40 positive supply is received which is given to positive supply pin number 8 of VSB supply CPU FAN Supply Controller IC U/S (LM358). VSB supply is used in the power control section.

Testing of +5VALWP and +3VALWP main section power supply section

This section would be check when there is no supply of +5VALWP and +3 VALWP at motherboard of laptop. And laptop doesn’t in the on state after pressing power button. For this different components and signals are checked situated on this section.

CHECK:- Main Power Supply Controller Chip PU5(MAX1999 or MAX 8734), MOSFET PQ 10, PQ 11(A04912), B+ power supply, MAINPWON signal, VS supply, diode PD 10, resistance PR 56, PR 171, PR 59, coil PL4, PL5, PL6 etc.

4.EMBEDDED Controller (micro Controller) Section.

The main work of this section has to control battery charging DCIN section MAIN power controller section, section power controller, keyboard touchpad, mouse flash Rom Bios, indicator LED laptop ON/OFF FAN, LCD panel and inverter. For this in laptop Acer Travel mate 2400’s section Embedded controller U20 (KB910-B4) has been used. Same number of embedded controller does not work from one laptop to another laptop. EC of one laptop can work in second laptop but the two laptops are of same brand and same model. In controller, RAM, ROM, clock generator, section controller, and port section can be made on same chip.

Different sections are made inside the Embedded controller (EC) IC U20 for controlling the Laptop totally. Description of these section are follows:-

(i) Power Supply Section:- Embedded controller VCC, VCCA, VCC BAT pins are positive input supply pins of section in embedded controller. +3VALW supply received from main power controller is given to power supply section. All section of embedded controller are received supply through +3VALW.

(ii) LPC interface section:-Super I/O controller and ICH chip are being connected by LPC interface section of embedded controller. It is a low pin count bus. Embedded controller chip connection is done through this bus ICH6M chip. Data being transferred between ICH and embedded controller by this bus.

(iii) X-Bus Interface Section:- Flash ROM is being connected by this X-bus interface section of embedded controller. By this section programs of bias are read and write. Bios’ post program can be run by this-bus interface.

(iv) PS2 interface section:- Through this section of embedded controller touch pad, mouse board control. It means through PS2 interface section touch pad will work.

(v) SM Bus Section:- In this section two buses are work. By one bus laptop battery and EC memory would be connected, due to which information of battery of laptop received and all the setting data of laptop is saved by this bus in EC memory and through second bus made in this section received information about temperature of laptop. That means its connection is with thermal connection temp monitoring IC.

(vi) GPIO(general purpose input/output) section:- Program of this section of embedded controller are controls the laptop according to the pins of given port through VRAM_ON, SUSP#,BT_ON#, LID_SW#, PBTN_OUT# and SYS_ON. It means that Inverter section, LCD Panel Section, Bluetooth Section, CPU_Core power supply is ON/OFF through this section.

(vii) Time Section: - This part of embedded controller is used to control the timing of clock of EC and rest. It’s connection is by done ICH6M chip.

(viii) Internal Keyboard Section:- Keyboard of Laptop is connected by Internal Keyboard Section of Embedded Controller, by which signal of given command are received to this section by keyboard.

(ix) Pulse Width Section:- Main work of pulse width section of Embedded section is to control the Invert PWM control, beep signal out, AC OFF, EC ON, EC MUTE. Means controls related to pulse width section are control by this section.

(x) WAKE UP Pin Section:- Through the Wake UP Pin Section of Embedded, sense the ON signal of different supplies of Laptop. By this section ON/OFF, AC IN, PM_STP_S3#, PM_SLP_S5#, EB_BT# signals are input/output is done.

(xi) Analog to Digital Section:- Through the Analog to Digital section of Embedded, sense the temperature of battery, over voltage protection of batteries and NBA_PLUG_M Signal and sensing signals are connect in the analog to digital section thgough this section and control signal are out by second section.

(xii) Digital to Analog section:- Digital to Analog section of Embedded controller is used to convert signals from digital to analog and taken out. Some other signals are also out through this section which is as: - DAC_BRIG signal for controlling the brightness of inverter section, IREF signal of battery charging, EN_DFAN1 signal of CPU FAN supply controller section, WL_ON (Wireless ON) signal of Mini PCI Slot section and amplifier Mute signal of Audio Amplifier section.

(xiii) Expanded I/O section:- Through Expanded I/O section of Embedded controller ON/OFF volt are provided to all the indicator of Laptop. Through this section supply is given to power LED, power SUSP LED, battery Full LED, battery charging LED, wireless on LED, Bluetooth on LED, email LED, and media LED. Negative supply is given to all these LEDs through this section and positive supply is received from power supply section.

(xiv) FAN SECTION:- Through FAN section of Embedded controller CPU Fan speed is sensed & control its speed.

5.FLASH ROM (Bios) Section

The most important work of this section is to providing CPU post signal to Laptop computer at the time of power ON. By which CPU can detect the hardware fitted on the motherboard according to this signal. BIOS is a software. This software is writing according hardware fitted on the motherboard, due to which CPU get all the information about all the hardware at the time of POWER ON. This software is written by Laptop manufacture. BIOS run this software by CPU, connecting the ROM IC at motherboard and storing the software inside the ROM IC. Storage of this Flash ROM is 4MB and this IC is made by using the 512 KBx8 memory bank in it. Data stored inside this IC is stored for 100 years. Sector erases time of this IC is 18 ms and chip erase time is 70 Ms. Bright program of this IC is 14µs & Rest time is 8 seconds. For interchanging the Data Bus in this IC (Farmeware) Hub Interface (FWH) mode is used for system.

Flash Rom (Bios) Circuit Diagram of Acer TravelMate 2400/3210/3220 Laptop

ROM IC U42 (SST39UF040) connecting in the Flash ROM BIOS is 32 Pin IC. To whom +3VALW supply, received from +3VALW Main power supply is given to pin no.32 of IC U42 and the negative supply is given to pin no. 16 of IC U42.

MOSFE Q21 (2N7002) & OR gate are used for Write Enable of IC U42. +3VALW supply is given at pin no. 5 and negative supply is given at pin number 3 for working the U23. FWR# signal is given at input pin no. 1 of IC U23 from Pin no. 151 of EC IC (U20). Pin no. 2 connected with the drain of MOSFET Q21. +3VALW supply is given to the drain of MOSFET Q21 through the resistance R3335 (100K0. EC_FLASH# signal is given at the source of MOSFET q21 from pin no. T3 of ICH6M CHIP U13. SUSP# signal is given at the Gate of MOSFET Q21 from pin no. 149 of EC IC(U20). During SUSPENSE mode we get low signal on the gate of MOSFET Q21, which result in the off state of MOSFET and we get high on the pin number 2 of IC U23, which implies the high out through the output pin number 4 of IC U23 and also high on the write enable pin of flash ROM which leads to the disable of Flash Rom, when we get low on pin number 1 and 2 of IC U23, then flash Rom IC U42 is write enable.

Low signal are received in the form of FRD# signal at pin no. 24 of IC U42 from pin no. 150 of EC IC U20 for Enable the output of Flash ROM IC U42. Low signal are given in the form of FSEL# at pin no. 22 of IC U42 from pin no. 173 for Enable the Flash ROM Chip. Then Flash ROM Chip starts the work.

Address and data of flash Rom IC is connected to the data pin of EC IC U20.KBA0 to 19 of address and ADB0 to 7 Data are used.

6. Embedded Controller Memory Section

The main work of this section is to control the laptop computer and saving the adjustment. It means that when laptop becomes ON, then its information of setting is in this memory. Embedded controller of this memory, according to the saved setting after read, Laptop is given the display and do the work. In this section IC U21 (AT24C16An) memory IC is fitted. For EC memory two wire serial EEPRON is connected, EC memory U21 (AT24C16An) is 8 pin IC, its pines description are given below.

Pin no.1, 2 and 3: A0-A2: These pin are address input.

Pin 4: GND: This is negative supply pin

Pin 5:SDA: This is Serial Data pin.

Pin 6: SCL: This is input pin of serial clock.

Pin 7:WP:This is pin of write protect.

Pin 8: VCC: This is pin of positive supply.

+5VALW supply is given to pin number 8 of IC U21

+5VALW supply is given at pin number 18 of IC U21 for work of EC memory section. Write protect pin of IC U21 is connected with pin of address A1 and A2. +5VALW supply is given to address A0 by resistance R315 (100k). Pin number 5 and 6 of data and clock of ECSN bus are connected with pin number 164 and 163 of IC U21 of embedded controller. Data being read and write in memory with the help of ECSN bus data and clock.

Testing of embedded controller section, flash ROM (bios) section and EC memory sections

These all sections are checked when laptop does not ON after switching ON the power and charging power ON LED status does not give response. For this these 3 sections are checked by component, supply and signal.

Check: Embedded controller chip U20 (KB910-B4), crystal oscillator X1 (32.768 KHz), flash ROM IC U42 (SST39VF040), Embedded controller memory V21 (AT24C16AN), supply of +3VALW, +5VALW and ECRST# signal etc.

7. 1.5VALWP & 1.8VP (RAM) SYSTEM POWER SUPPLY SECTION

Main work of this is to making two regulated supplies +1.5VALWP & 1.8VP from B+ supply received from Battery charging & Power Selector, providing regulated supply of +1.5VALWP to stage & RAM slot made on the motherboard. In this section power MOSFET PQ25, PQ26 (A04422x2), PQ27, PQ313 (A04702x2) PWM controller IC PU9 (ISL6227CA) is 28 pins IC. The details of these pins according to the figure are as follows.

Description of 1.5VALWP & 1.8 VP (RAM) SYSTEM POWER SUPPLY SECTION

B+ received at pin no. 14 of PWM Controller IC PU9 from battery charge & Power selector through coil (PL13), resistance PR137 (OE). Supply received from coil (PL13) is known as B++++. +5 VALWP supply get from +5 VALWP and +3 VALWP main power supply is supplied to pin number 28 of PWM controller IC PU9 by resistance PR 156 (2.2E). Pin number 1, 3 and 26 of IC PU9 are given the negative supply, which is ground in circuit. For active both the channels of IC, pin number13 of IC PU9 is ground. Supply of both channels of IC PU9 is from soft start pin number 12 and 17 by which capacitor PC 106, PC112(0.01MFx2) has been grounded. Boot 1 and boot 2 is supply of +1.5VALWP.

For setting the oscillation of both channels, PR157(71.5K) is ground from pin no. 11 and PR158(80.6k) is ground from pin no. 18.

To get +1.5 VALWP regulated supply we used the power MOSFET PQ25(A04422) and PQ 31 (A04702). B++++ positive supply given to pin 5, 6, 7 and 8 of drain of MOSFET PQ25. Pin number 4 of gate of MOSFET PQ25 is connected with pin number 5 of upper gate drive out PQ25.

Pin no.1, pin no.2, pin no.3 is connected with pin no.5, 6, 7 & 8 of drain of lower MOSFET PQ31. The pin no.1, pin no.2, pin no.3 of the source of PQ 31 is ground. The gate of MOSFET PQ31 is connected to lower gate drive out pin no.2. When there is +5VALWP at pin no.8 of IC PU9 (ISL 6227CA). Then pin no.2 pin no.5 out the MOSFET gate drive pulse. By which the MOSFET switching process, it create regulated +5VALWP with the help of B+ supply. Which is received by the coil (PL). Capacitor PC104(150MF) is used for filter the +5VALWP supply. To stabilize the output supply, the +5VALWP supply is given to the pin no.9, pin no.10 of the IC PU9.(ISL 6227CA) by the divider circuit. When changes occur in the +5VALWP supply, then it is controlled by the pin no.9 & pin no.10 of IC PU9 (ISL 6227CA).

Power MOSFET PQ26 (A04422) and PQ27(A04702) is used to get the +1.8 VP supply. The pin no.5, pin no.6, pin no.7, pin no.8 of the MOSFET PQ25 is given B++++positive supply. The gate pin no. 4 of the MOSFET PQ26 is connected to the upper gate out put pin no. 24 of the IC PU9 (ISL 6227CA) the source pin no.1, pin no.2, pin no.3 of MOSFET PQ 26 is connected with the drain pin no.5, pin no. 6, pin no.7, pin no. 8 of the MOSFET PQ27. The source pin no.1, pin no.2, pin no.3 of MOSFET PQ26 is grounded the gate of MOSFET PQ27 is connected with the lower gate out drive pin no.27 of the IC PU9(ISL 6227CA). When the SYSON signal from the pin no. 148 of EC IC (U20) is received on the pin no. 21 of the IC PU9 (ISL 622CA), then MOSFET gate drive pulse are out from the pin no.24, pin no27 of the IC PU9 (ISL 6227CA) by which the MOSFET perform switching, by which +1.8VP’s regulated supply is created of the B+ which is received by the coil PL 15 to filter this capacitor PC 114 is set up to stabilize the out supply, the +1.8VP supply is given to the pin no. 19, pin no. 20 of the IC PU9 (ISL 6227CA) by the divider circuit when changes occur in the +1.8VP supply, then it is controlled by the pin no. 19 & pin no.20 of IC PU9(ISL 6227CA).

+1.5VALMP & 14.8 VP (RAM) system power supply division testing

This division is checked when the RAM in the motherboard in the laptop does not give supply or motherboard does not received the +1.58 VALWP & 1.8 VP supply. Due to which the laptop does not starts. For this the following component, power supply and signal are checked.

Check:- PWM controller IC PU9(ISL 622CA), MOSFET PQ 25, 26, 27, 31 diode PD 22, coil PL 13, 14, 15, resistance PR137, 156, supply B+, +5VALWP, SIGNAL +5VALWP, SYSON ETC.

8. +2.5 VP System Power Supply section

the main working of this division is to create +2.5V regulated supply by the received +3VALWP and +5VALWP from the main power supply division in this division linear regulator and MOSFET PQ 41 is use to make this division they got +2.5 VP supply is given by the jumper PJP9 to LCD division GMCH chip.

+2.5 VP SYSTEM power supply division circuit description :- The liner regulation IC PU11(CM85621S) is a 8 pin IC, whose pin description is given below:-

Pin no. 1-VIN-this is input power supply pin for the IC.

Pin no. 2-VFB-this is feedback pin of VOUT of the IC,

Pin no. 3,4-VOUT-this is volt out pin of IC

Pin no. 5-REFEN- this is reference voltage input and chip enable pin of the IC

Pin no. 6VCCA- this is voltage supply pin if internal circuit.

Pin no. 7 AGND-this is analog ground pin

Pin no. 8 PGND-this is power ground pin

+2.5VP System Power Supply Circuit DIAGRAM OF Acer TravelMate 2400/3210/3220 Laptop

The supply of +5VALWP and +3VALWP is provided to pin no. 1 of IC PU11 through jumper PJP12. The supply of +5VALWP is given to pin no. 6 of IC PU11 through jumper PJP8IC. Then pin no. 7 and 8 of ICPU11 is being grounded. When there is a RTCVREF volt resistance no pin no. 5 of ICPU11 through PR179 (64.9K), then there is a regulated output supply of +2.5VP on pin no. 4 and 5 of ICPU11. To stable the regulated supply of +2.5VP it is given to pin no. 2 of ICPU11, so there is no alteration in output supply and it can be easily controlled, due to which we obtain a constant supply of +2.5VP.

When the SUSP signal in form of high from collector of transistor Q25 is given to gate of MOSFET PQ41, then MOSFET turns ON and lowers the supply of pin no. 5 of IC PU11, due to which there is stoppage in flow of voltage out from pin no. 3 and 4 of IC PU11.

Testing of section of +2.5VP system power supply:-

This section is checked when, we do dot get the supply of +2.5VS from laptop’s motherboard. For thgis check following components & power supply connected in this section:-

Check:- Linear regulator ICPU11 (CM85621S), MOSFET PQ , jumper PJP12, supply +3VALWP, +5VALWP, RTCREF etc.

9.+0.9VP system power supply section:-

The main work of this section is to make the regulated supply of +0.9VP with the help of supply +1.8 VP and +3VALWP. This section is made by using the 3A Bus Termination Regulator IC PU12 (APL5331KAC) and MOSFET PQ30 (2N7002). The supply +0.9VP obtained from this section is used for VTT supply of RAM by jumper PJP7.

Explanation of +0.9VP system power supply:- The 3ABUS Termination regulator IC PU12 (APL5331KAC) connected in this section is 8 pin IC. Whose pin types are as follows:-

+0.9VP System Power Regulator Circuit Diagram of Acer TravelMate 2400/3210/3220 Laptop

Pin no. 1-VIN-This is the IC’s power supply input pin.

Pin no. 2-GND-This is IC’s power and signal ground pin.

Pin no. 3-VREF-This is input pin of IC’s reference volt.

Pin no. 4-VOUT-This is IC’s regular output pin.

Pin no. 5, 7&8-NC-This IC’s No Internal Connection pin.

Pin no. 6-VCTNL-This is power input pin of internal control circuit of IC.

To keep working, this section is provided with the supply of +1.8VP to the pin no. 1of ICPU12 through jumper PJ2. There is supply of +3VALWP to the pin no. 6 of internal circuit of PU12. There is negative supply provided to IC PU12 through pin no. 2. Through the voltage obtained on pin no. 1 we give the reference volt to pin no. 3 of IC PU12 through divider circuit. When we obtain the reference volt at pin no. 3 then we get the regulated output supply of +0.9VP at pin no. 4 of IC PU12. In the suspense Mode, When the SUSP signal in from of high from collector of transistor Q25 is given to gate of MOSFET by which it low the reference volt as it get on by which the IC gets shut down, and the supply from the volt out [in stops.

Testing of +0.9VP System Power Supply Division:-

This division is checked, when the RAM does not get the Vtt supply. For this the following components are checked.

Check: - Bus termination Regulator IC PU12 (APL5331KAC), Mosfet PQ30 (2N7002), jumper PJP, resistance PR159, supply +1.8VP, +3VALWP etc.

10. CPU Fan supply Control Division

The main work of this division is to control the +5VS and provided it to the CPU Fan supply. This division is basically made up of MOSFET PQ40 (TPO610K), PQ30 (2N7002), Q15 (SI3456DV) Dual operational amplifier IC U15 (LM358). To make this division work a power supply of +B, +5VS and +3.3VS is required.

Description of the circuit of CPU Fan supply Control Division :- To make this division work properly, a B+ supply is send to the power source of MOSFET PQ40 at pin no. 3. For the B+ supply we use battery charging and power select division. A negative signal is required by the MOSFET PQ40 at its gate, to get the MOSFET PQ40 in ON status because PQ40 is a P-channel mosfet. MOSFET PQ39 (2N7002) is used to give negative supply. When the pin no. 2 of PU5 sends a SPOK signal as the gate of the PQ40, this makes the PQ40 get ON and it sends volt out through pin no. 1 of the drain, and this is knowledge as VSB volt. This VSB signal is passed to all the divisions. The VSB volt is also supplied to dual operational amplifier U15 (LM338) at pin no. 8.

To give supply at pin no. 1 of CPU Fan connector JP21, the drain pin no. 1, 2, 5 and 6 of the Mosfet Q15 (SI3456DV) are used to given a supply of +5VA. The source of mosfet Q15 is connected with pin no. 1 of the CPU Fan connector JP21. A positive volt is required at the gate of mosfet Q15 to switch it ON. This positive volt is received from pin no. 1 of IC U15, but the positive volt from pin no. 1 of IC is not send out till the pin no. 3 of IC U15 not receives a high EN_DFAN1 signal from the pin no. 102 of EC IC U20. When high signal is receive at pin no.3 of U15, it is send out through the pin no. 1 of U15, which is given at the gate of mosfet Q15, this switches ON the mosfet and the volt passes from drain to source, by which positive supply is given of CPU FAN through pin no. 3 of connector JP21. To sense the speed of CPU FAN, Fan_Speed1 control signals are send out through the pin no. 3 of the CPU FAN connector JP21, and these signals are given to pin no. 171 of EC IC U20.

Testing of CPU FAN Supply Control Division

This division is checked when the CPU FAN does not get the supply or the Laptop after starting gets OFF immediately. This means that the CPU FAN is unable to get the power supply. For this, the following components and signal are needed to be checked.

Check:- Mosfet PQ40, PQ39, Q15, IC U15, CPU FAN connector JP21 , diode D26, Supply VSB, +5VS, SPOK signal, EN_DFAN1, etc.

11. +3VALW to +3VS Supply Power control Division

The main work of this division is to control the supply and distribute it to different division with the name of +3VS supply from the +3VALW received through the +3VALW Main power supply division. The division is basically made up mosfet U11 (SI4800DY) and mosfet6 Q12 (2N7002). The +3VS supply received from this division are send to all other divisions in the laptop.

1. CPU Core power supply Division

2. +1.5VP System power supply Division

3. Embedded controller (Micro controller) Division

4. GMCH Division

5. RAM slot Division

6. Clock Generator Division

7. LCD power Circuit Division

8. LCD panel Division

9. ICH6M (South Bridge) Division

10. PCMCIA Controller Division

11. PCMCIA Power Controller Division

12. LAN Controller Division

13. Mini PCI Slot Division

14. Audio Codec Division

15. Fan supply controller division

To make this section in the section in the working position, the pin no. 5, 6, 7 and 8 of the drain of power mosfet U11 are connected to a supply of +3VALW. When the pin no. 4 of the gate of the power mosfet U11 is given VSB supply through the resistance R161 (100 K), then a supply of +3VS is send out through pin no. 1, 2 and 3 of the source of power mosfet U11.

At the time of suspense mode , the gate of mosfet Q12 receives a SUSP signal from the collector of transistor Q25 at high from the pin no. 4 of the power mosfet U11, due to this mosfet Q12 gets ON and the gate of power mosfet U11 gets low. So, the supply from the source of U11 stops. The positive supply received at the gate of the power mosfet U11 is called as 5VS_GATE, which is supplied to different divisions.

12.+5VALWP to +5VS supply controller division:-

The main work of this division is to control the supply and distribute it to different divisions with the name of +5VS supply from the +5VALW received through the +5VALW Main power supply division. The division are send to all other divisions in the laptop.

1. CPU Core Power Supply Division

2. External Display Port Division

3. ODD Connector Division

4. HDD Connector Division

5. PCMCIA Power Controller Division

6. Mini PCI Slot Division

7. Audio Power supply Regulator Division

8. Mouse Touchpad Division

9. Internal Keyboard Division

10. Fan Supply Controller Division

11. LED Indicator Division

For working this section, pin no. 5, 6, 7 and of the drain of power mosfet U45 are connected to a supply of +5VALWP. 5V_GATE signal is given in the form of high at the gate of power mosfet U11 connected in the +3VS supply controller stage from the gate of power mosfet U45 then the pin no. 1,2 and 3 of power mosfet U45 gives out a power supply of +5VS, which is given to the different sections. At the time of suspense mode, the gate of the power mosfet U45 receives a 5 VS_GATE, i.e. this pin received a low signal and this makes the power mosfet go OFF. So, the different divisions stops getting the power supply.

13. +3VALW to +3VS supply controller division:-

The main work of this division is to control the supply and distribute it to different divisions with the name of +3VS supply from the +3VALW received through the +3VALW Main power supply division. The division is basically made up of mosfet U11 (S14800DY) and mosfet Q24 (2N7002). On the basis of thr received +3V. This available +3V supply is provided to LCD power control, Mini PCI socket, Beep sound control IC, modem data daughter card and power on circuit division.

To make the power mosfet U43 work, pin no. 5, 6, 7 and 8 of drain of power mosfet U43 are given a supply of +3VALW. When VSB supply via resistance R340 is given on the gate of mosfet U43 pin no. 4, then source pin no. 1, 2, 3 of a power mosfet U43 outs +3V, which is given to different divisions. SYSON# signal in the from of low is received from the controller of gate co transistor Q22 of mosfet Q24, which is on the pin no. 4 of the power mosfet U43 at the time of system ON, Due to which mosfet Q24 is remain off and high is obtained at the gate of power mosfet U43. That is why, +3V is received at the source, of source of power mosfet U43. During system off, high is obtained at the gate of power mosfet Q24. Due to which it put OFF the power mosfet U43. So, +3V is not obtained at source.

14.+1.8V to +1.8VS supply power control division:-

The work of this division is to distribute the +1.8VS to different divisions of the laptop, which is received from diffe3rent from the +1.8V system power supply division. The division is basically made by using a power mosfet U12 (SI4800DY). The supply of 1.8 VS received from this division is supplied to the different divisions of the Laptop.

To make this division work, pin no.5, pin no.6, pin no.7 & pin no.8 of the drain of the power MOSFET is given +1.8 V supply. When +3 VALW to +3VS supply in high from is given on the pin no.4 of power MOSFET gate by the 5VS-gate signal received at gate of power MOSFET U11 in controller division, the source pin no.1, pin no.2, pin no.3 out +1.8 VS of power MOSFET U12, which is given to the different division.

During the Suspense Mode, the gate of power MOSFET does not get 5VS-GATE signal means this pin out low by which the power MOSFET is off, due to this, the +1.8VA supply is not received by the different division .

15.+1.5 VALW to +1.5 VS POWER SUPPLY CONTROL DIVISION

The working division is to control the +1.5 VALW supply from the +1.5VALW system power supply division to +1.5 VS supply, and give to other parts. This division is made by power MOSFET U 17 (SI 4800DY). The received +1.5 VS supply from this division is given to north bridge and the south bridge division of LAPTOP.

The +1.5 VALW supply is given at the pin no.5, pin no.6, pin no.7 & pin no.8 of drain of power MOSFET U 17 when +3 VALW to +3 VS supply in high from is given on gate on gate of the power MOSFET U 17 by the 5VS-gatesignal received at gate of power MOSFET U11 in controller division, the source pin no. 1, pin no. 2, pin no. 3 +1.8 VS of power MOSFET U17, which given to the different division.

During the Suspense Mode, the gate of power MOSFET does not get 5VS –GATE signal means this pin out low by which the power MOSFET is off, due to this, the +1.5 VS supply is not received by the different division.

TESTING OF +3VS, 5VS, +3V, 1.5 VS & +1.5 VS SUPPLY POWER CONTROL DIVISION

The main section is checked when, we do not get the supply on power controller division on the motherboard on laptop’s motherboard. Then the following component are checked.

CHECK:- for +3 VS supply for MOSFET U11, Q 12, for +5 VS supply for MOSFET U45, for +3 VS supply for MOSFET U 11, Q 12, for +5VS supply for MOSFET U45, for +3 VS supply for MOSFET U43. Q24, for +1.8 VS supply for MOSFET U12,for +1.5VS supply for MOSFET U17 and etc.

16.+1.05VP SYSTEM POWER SUPPLY DIVISION

The main working of this division is to regulate the +B supply from battery charger and the power selector division into +1.05 VP in this division, power MOSFET PQ 32 (A04912) and step down controller IC PU8 (MAX 8578E) is used, by which these division are made the +1.05 VP from this division are made the +1.05VP from this division is given by jumper PJP 10 to CPU and GMCH (north Bridge) division.

The step controller IC PUB 8, used in +1.05VP system power supply stage is 10 pin IC. The description of the pins is given below:-

Pin no. 1 this is feedback pin of the IC.

Pin no. 2 this is soft start pin of the IC by grounding the capacitor on this pin soft start time is adjusted.

Pin no. 3 this is supply input pin of the IC on which 3 V to +5.5 V supply is given.

Pin no. 4 this is ground pin of the IC

Pin no. 5 this is low side gate driver output pin of the IC.

Pin no. 6 this is boot pin of the IC.

Pin no. 7 this is external inductor connection of the IC.

Pin no. 8 this is high slde gate driver, output pin of the IC.

Pin no. 9 this is enable pin of the IC.

Pin no. 10 This is over current limit set pin of the IC.

+1.05 system power circuit diagram description:- pin no. 3 is given +5VALWP and pin no. 4 is given the +V supply of IC PU8 (MAX 878E) means ground is given on the pin no. 4.

+5VALWP supply is given on the BST pin by diode PD 25 (IS 5355) of the IC PU8 (MAX 8578E), when pin no. 9 is given +3 VS of IC PU8(MAX 8578E), then +3 VS is received on the pin no. 9 of IC PU8(MAX8578E) then MOSFET gate drive pulse is out from the pin no. 5 and pin no.8 of the IC PU8 (MAX 8578E), which is given on the pin no. 5 and pin no.5 of the power MOSFET PQ32 on the pin no. 1 & pin no. 2 of drain of the power MOSFET PQ32, +B supply from battery charger and the power selector division is given by the coil. Power MOSFET PQ 32 is 8 pin dual N-channel MOSFET, in which pin no. 4 of the source gate is ground when gate drive pulse is received from the step down controller IC, then by the drain 1 and source 2 pin no.5, pin no. 6, pin no. 7 out a regulated supply which get filter by coil (PL17) and capacitor PC 137 (220 MF) for stabilizing the +1.05 VP, the +1.05VP supply is given in the from of feed back to pin no. 1 of IC PU8(MAX 8578E) by the divider circuit when there is a change in the output volt due to some reason, then there is a change in the feedback pin voltage, which is sensed by the IC, and control the output voltage, +1.05 VP supply is given to the different division via jumper PJP10 to +1.05 name divisions.

Testing of system power supply section-

We check this section when we do not get +1.05 volt of supply in the mother of laptop. For this we check the following component of the power system supply section.

CHECK- Step down controller ICPU(MAX8578) MOSFET PQ32, coil PL17 PL18 etc.

17. POWER DISCHARGE CIRCUIT STAGE

The main purpose of this is to discharge the different output supply during the suspense mode or when the laptop is in power OFF mode so that any section does not get damaged by working on low voltage. This section made by using MOSFET Q41, Q14, Q17,Q13(2N7002x4) and transistor Q25 (DTC115EKA). To make power discharging circuit section work the source of all the MOSFET are grounded and gate is connected with the collector of transistor 225.The drain of MOSFET Q41 is connected to +5VS through resistance R609 (470E), drain of Q14 is connected to +1.8VS through resistance R169 (470E), drain of Q17 is connected to +1.5VS through the resistance R200 (470E), the drain of Q13 is connected to +3VS through the resistance R156 (470).

At the collector of transistor Q25 a supply of +5VALWP is given through the resistance R343 (10K). In the normal state the transistor Q25 remains ON because of which all the MOSFET are OFF state. When the SUSP# signal in the from of LOW gets available at the base of transistor Q25 then the transistor goes OFF and all the MOSFET’s gates gets a supply of +5VALWP through the resistance R343. Due to this all MOSFET goes ON due to which all resistances connected to the supply goes on load i.e. the connection of the resistance gets grounded, so all the supply gets discharged. From the collector of transistor SUSP signal is given to the MOSFET Q12, PQ30 and PQ41.

18. CPU CORE POWER SUPPLY SECTION

The main purpose of this section is to regulate the volt, received from battery charging and power selector stage switching by B+ supply & provide the CPU core voltage to the CPU, boosting the current. For this in this section we use N-Channel power MOSFET PQ14, PQ19, (AO4408x2) and PQ16, PQ22 (AO4410x2), programmable PWM controller ICPU7 (MAX1532AETL). Input power +5VS and B+ is given for working the CPU core power sup[ply section. In the from of input signal VR_ON, PM_STP_CPU#, PM_DPRSLTVR, PSI# and CPU_VDD 0-5 signal are given. When input power and input signal are available in this section starts working and VGATE signal and +CPU_Core voltage send out. It sends out +CPU_Core voltage. This +CPU_Core supply is given to the CPU.

Circuit description of CPU_Core power supply section-The programmable PWM controller chips present in this section are of PU7 (MAX 1532AETL) 40 pin. The descriptions of the pin are as follows:-

Pin number 1-TIME-This is Slew rate adjustment pin of IC.

Pin number 2-TON-This is ON Time selection control input pin of IC.

Pin number 3-SUS-This is suspend input of IC.

Pin number 4,5-SO,SI-This is input pin of suspend mode voltage selector of IC.

Pin number 6-SHDN#-This is input pin of shut down control of IC.

Pin number 7-OFS-This is voltage divider input pin of OFFSET control of IC.

Pin number 8-REF-This is the output pin of 2 V reference of IC.

Pin number 9 –ILIM-This is the current limit adjustment pin of IC.

Pin number 10- This is input pin of voltage supply of analog section of IC.

Pin number 11-GND-This is pin of ground of analog section of IC.

Pin number 12-CCV-This is the pin of voltage integrator capacitor connection of IC.

Pin number 13-GNDS-This is input pin of ground remote sense of IC.

Pin number 14-CCI-This is the pin of Current Balance compensation of IC.

Pin number 15-FB-This is the input pin of feedback of IC.

Pin number 16-OAIN-This is the input pin of Operational Amplifier Inverting of IC.

Pin number 17-OAIN-This is pin of Operational Amplifier Non Inverting of IC.

Pin number 18-SKIP-Tis is the input pin of pulse skipping select of IC.

Pin number 19-24-D5-D0-This is the output pin of VID DAC of IC.

Pin number 25-VROK-This is output pin of power good of IC.

Pin number 26-BSTM-This is input pin of Main Boost Capacitor Connector of IC.

Pin number 27-LXM-This is the pin of main inductor connection of IC.

Pin number 29-DLM-This is output pin of main low side gate drive of IC.

Pin number 30-VVD-Tis is positive supply pin of IC.

Pin number 31-PGND-This is the pin of Power ground of IC.

Pin number 32-DLS-This is the output pin of secondary low side gate driver of IC.

Pin number 33-DHS-This is the output pin of secondary high side gate driver of IC.

Pin number 34-LXS-This is the input pin of secondary inductor connector of IC.

Pin number 35-BSTS-This is the pin of secondary boost capacitor connection of IC.

Pin number 36--V+-This is input pin of battery voltage sense connection of IC.

Pin number 37-CNP- This is the input pin of main inductor positive current sense of IC.

Pin number 38-CMN-This is the input pin of main inductor negative current sense of IC.

Pin number 39-CSN –This is the input pin of secondary inductor negative current sense of IC.

Pin number 40-This is input pin of secondary inductor positive current sense of IC.

To get the CPU Core voltage, two phase supply is used in this section. For both main and secondary phase two MOSFET and two inductor coils are used.

The +B supply from the battery charging and power selector division is received via a coil PL8 on the pin no.5, 6, 7, 8 of the drain of high side power mosfet PQ14, which is attached in main phase.

The source pin no. 1, 2, 3 of PQ14 mosfet is connected to drain pin no. 5, 6, 7, 8 of low side power mosfet PQ16. A supply of regulated main phase from the pin s of source and drain of PQ14 and PQ16 are received, these are received, these are received by the coil PL9.

High side gate drive pulse is given at pin no.4of main power mosfet PQ14 from pin no.28 of programmable PWM controller IC PU7 & Low side Gate drive pulse is given at pin no.4 of main power mosfet PQ16 from pin no. 29 of programmable PWM controller IC PU7. Pin no. 1, 2 and 3 of source pin of MOSFET PQ16 is grounded. When high and low side gate drive pulse power from pin no.28 and 29 is sent to the gates of PQ14 and PQ16 then power MOSFET creates a regulated volt using switching principal which is according to the given gate pulse. Regulated volt which we get is out from coil (PL9). In order to sense the current which is received on coil PL9, pin no. 37 and 38 of IC PU7 is connected, by which controls the supply of current.

In order to get phase regulated supply, we are using secondary power MOSFET PQ19 (AO4408) and PQ22 (AO4410). Battery charging from pin no. 5, 6, 7 and 8 of drain of high side power MOSFET PQ19 and B+ supply coil (PL8) from power selector section. Pin no. 5, 6, 7 and 8 of low side of drain of power MOSFET PQ22(AO4410) and pin no. 1, 2 and 3 of source of power MOSFET PQ19 1, 2 and 3 of source of power MOSFET PQ22 are grounded.

Pin no.4 of secondary 1, 2 and 3 of source of power MOSFET PQ19 GETS HIGH SIDE GATE BDRIVE PULSE FROM PIN NO.33 of IC PU7, and pin no.4 of secondary 1, 2 and 3 of source of power MOSFET PQ19 of PQ22 get low side gate drive. When pin no. 33 and 32 gives out low and high side gate drive pulse gives to 1, 2 and 3 of source of power MOSFET PQ19, through switching principal creates a regulated volt. This is according to the gate pulse . Inputted regulated volt is outputted from drain and source junction pin of MOSFET PQ19 and PQ22 , which is outputted from coil PL10.

In order to sense the current which we get from coil PL10, pin no. 39 and 40 IC PU7 are to be connected, through which supply current is controlled. After connecting main phase of coil PL9 and secondary phase coil PL10, we get +CPU_DORE supply. In order to work the CPU CORE the conditions are:

2V on pin no.8 of IC PU7, high on pin no.6, high on pin no. 7, high on pin no. 3 and low on pin no.18 should be given.

When CPU CORE does correct function then we receive VGATE in the form of CPU CORE on pin no. 25 of IC PU7. If on this pin Supply is low. The means that CPU CORE is not working. Then VGATE is given to clock generator section, south bridge (ICH6M) and GMCH (north bridge) so that this section starts working.

Testing of CPU Core Power Supply Section

This section being checked when CPU does not received CPU Core supply it means that CPU not heated up after power ON the laptop charging after applying the supply. For this the following component and supply are checked:

Check: CPU CORE POWER CONTROLLER CHIP PU7, MOSFET PQ14, PQ16, PQ19, PQ22, COIL PL8, PL9, PL10, RESISTANCE PR 89, PR 90, SUPPLY CPU B+, +5VS1, 3VS SIGNAL VR_ON, PM_STP_CPU#, PM_DPRSLPVR, PSI# and CPU_VID0_VID5 etc.

POWER ON CIRCUIT SECTION

This section has significance to sense the supply and send the information of system power OK to south bridge (ICH6M) U13. This section is formed by invert IC U34 (SN74LVC14AP). IC U34 is sharing its two gates . Pin no. 14 of IC U34 is getting +3V positive and negative supply is given to pin no.7.

When +3VS and +3V is inputted then circuit starts working. Supply of +3VS is sent to pin no, 9 of IC U34 through resistance R539 (180k), DUE TO WHICH low is outputted at pin no.8 of IC U34. This low signal is given to pin no.11, due to which high is received on pin no.10 of another gate, which is sent to pin no.AA1 in name of SYS_PWROK signal on south brigde (ICH6M) U13, which is sensed by chip IC6 that system power is working correctly or not?

TESTING OF POWER ON CIRCUIT SECTION

This section is checked in that condition when SYS_PWROK signal is received by bridge chip. For this the following components are being checked:

Check: IC U34, RESISTANCE R539, SUPPLY +3VS and +3V, etc.

20. POWER BUTTON AND LUNCH KEEG SECTION:

(i) Power Button Section:-Main function of this section is to bring the Laptop in ON state after pressing the power button. In this section mainly Micro switch SW3, Transistor Q2(DTC124EK), Mosfet Q29(2N7002)& Diode D

+(DAN202U) are used. +3VALW is given for working this section.

There are 6 pins Power Button. Out of those, 3., 4, 5 and 6 are grounded. Pin no. 1& 2 is connected with pin no. 1of diode cD16 (DAN202U). In order to start the laptop, as soon as we press the SW3 button, then ON/OFF BTN signal is receives from pin no. 1& 2 of switch SW3 in the from of low, which is given to pin no. 1 of diode D16. Signal receive from pin no. 1 of diode D146 is sent out from pin no.2 & 3. ON/OFF signal sent out from pin no. 2 of Diode D16 is given to pin no.2 of EC IC (U20), by which EC IC sense it that power button is pressed.

Signal sent out from pin no.3 of diode D16, is given to the gate od mosfet PQ1 as the name 510#, after this EC_ON signal is given at the base of transistor Q2 from pin no. 39 of EC IC (U20). Because of that, transistor becomes ON and do the pin no. 3 of diode in the low position for ever, by which low signal are receiving cintinously at the gate of mosfet PQ1.

At the time of laptop becomes off, high is given at pin no,2 of diode D16 by supply resistance R358(100K) of +3VALW & pin no. 3of diode D16 gets high from the gate of PQ1. Because of this, mosfet Q29(2N7002) becomes in the ON state & transistor Q2 has off.

Testing of Power Button

We check this section at that time when Laptop is not being ON by pressing the power button, means Embedded controller IC is not getting ON/OFF signal by pressing the power button of Laptop. For this check the following components of this section:-

Check:-Micro Switch SW3, Diode D16, Transistor Q2, Mosfet Q29 etc.

(ii) LUNCH MANAGER BUTTON: This is used according to the user. It is use3d according to the program manager of user. In this section 6 pin micro switch is used. Pin no. 5 and 6 of Micro switch is being grounded. When this button is used then embedded controller IC (U20) pin no. 153 has connection till the button is pressed, due to which EC IC (U20) senses that lunch manager button is pressed.

(iii) Email Button:- This button is used for lunching the Email Application. For this 6 pins micro switch is used. The pin no. 5 and 6 Micro switch SW2 is being grounded. When this button is used then pin no.153 of EC IC (U20) is connected to pin no. 74 of this IC only. This connection stays only till the button is pressed. EC IC (U20) senses this that Email button is pressed.

(iv) Acer Manager Button:- This button is used for managing program of Acer. For this 6 pin of micro switch SW5 is used. Pin no.5 and 6 of micro switch is ground. When this button is used then pin no. 153 of EC IC (U20) is connected with pin no. 71 of this IC. This connection stays only till the button is pressed. EC IC (U20) senses this t5hat Acer Manager button is pressed.

(v) Internet Button: This button is used for open the Internet Browser. For this 6 pin micro switch SW4 is used .Pin no. 5& 6 of micro switch is being grounded. Pin no. 3 and 4 is attached to pin no. 153 of EC IC (U20) and pin no. 1 and 2 is attached to pin no. 73 of EC IC (U20). When this button is pressed then the connection of pin no. 153 of EC IC (U20) is being done with pin no. 73 of this IC. These connections remain till only the pressed time of button, due to which EC IC (U20) senses this that Internal Button is pressed.

(vi) Wireless Button :-This button is used for enable and disable the Wireless Function. For this two pins micro switch SW8 is used. One side of this switch is being grounded and the other end is attached with pin no. 69 of EC IC (U20). When wireless function is disable and this button is pressed then pin no. 69 of EC IC (U20) gets the EN_WL# signal in the form of Low by switch SW8 by which wireless function is enable.

(vii) Blue Tooth Button:- This button is used for enable & disable the Bluetooth function. For this 2 pin’s of micro switch SW7 is used. One end of this switch is being grounded & second end is attached with pin no. 76 of EC IC (U20). When Bluetooth function disables and this time if this button is pressed then pin no. 69 of EC IC (U20) gets EN_BT# signal in the form of low by SW7 switch, due to which Bluetooth button becomes enables.

Testing of Lunch Keys Button Section

This section is checked at that time when the lanch key button of the laptop is pressed and it doesn’t work. For this, in this section the following components are checked.

Check:- The lunch key pressed and when it doesn’t work then with that switch related micro switch (SW2,SW4, SW6, SW7, SW8) are checked.

21. CLOCK GENERATOR SECTION:-

Main function of this section is to providing the CPU Free Clock pulse to the CPU & Clock pulse to other all sections by 14.318MHz crystal becoming ON & +3VS supply gets from +3VS power control. For this, clock generator IC U33(ICS954226AGT) and crystal (14.318MHz) is used for making this stage. Clock Generator IC comes of many companies like ICS MAX, IDT, WINBON, RTL, DELIS VIA etc.

Clock generator IC is a programmable IC. The programmable reveals that make ready the CPU Free Clock pulse according to the binary, gets on the FSA to FSC pins. Positive supply of +3VS is given at pin no.21, 28, 34, 37 & 42 of IC U33 connected in this section, by coil L32, which is known as +CLK_VDDI supply & +3VS positive supply is given at pin no.2, 6, 13, 29, 38, 45, & 51 are ground for Negative supply of IC. When IC gets positive & Negative supply. But till pin no. 10 of IC U33 doesn’t receive low signal, till then internal clock PLLs of IC and crystal oscillator are closed. To ON it, pin no. 10 of IC U33 attached to mosfet Q35 (2N7002)’s gate CPU Core power supply chip pin no. 25 of PU7 to VGATE signal is in the form of high, due to which mosfet Q35 gets ON and then pin no.10 of IC U33to supply +3 VS supply resistance R488 (10 E) is given. When low signal is received at pin no. 10 of IC U33 by mosfet Q35 then internal clock PLLs of IC crystal oscillator stage works and clock pulse of a particular value are prepare to ready with the help of crystal Y3(14.318MHz) connected at pin no.49 and 50 of IC, which are send out from pin no. 52 of reference clock output & given of CLK_ICH 14MHz clock pulse at pin no.E10of ICH6M U13 by resistance R514(12E), which are send out from pin no.43 and 44 of IC U33 & given to pin no.B14 and B15 of PGA478MB socket (JP20) through the resistance R490 and R497(33Ex2). When ICH6M, MCH and CPU receives clock pulse after that by clock generator section clock pulse is given to all the sections from different pin of IC U33. After that beside the ICH6M (U13) CPU, all the sections are given reset signal due to which, after getting the reset signal from GMCH(U31) ICH, given the reset signal to the CPU. After that CPU starts the working.

Testing of Clock Generator Section:-

This dept is checked at that time when on putting ON the power motherboard displays no and CPU does not received clock signal and CPU heats normal, then for clock signal in this dept following components, power supply and signal is checked.

Check:- Clock generator IC U33 (ICS954226AGT), crystal Y3 (14.318MHz), mosfet Q35 (2N7002), supply +CLK_VDD1, +CLK_VDD2, coil L32, L33, resistance R508, R517, R472, signal VGATE etc.

22. SYSTEM TEMPERATURE SENSING SECTION :-

Main function of this section is to sensing the temperature of system &given the information to EC IC (U20). This section is made by using the System Temperature Monitor IC U29(ADM1032R).

Circuit description of System Temperature Sensing Section:- The IC U29 (ADM1032AR), attached in this section is 8 pins IC, which pin description is as following type:-

Pin no. 1-VDD_ This is a positive supply pin of IC.

Pin no. 2-V+- This is a positive connection pin of Remote Temperature Sensor of IC.

Pin no. 3-D- -This is a negative connection pin of Remote Temperature Sensing of IC.

Pin no. 4-THERM#- It’s a ON/OFF throttle pin IC, to which pull up resistance is attached to positive supply.

Pin no. 5-GND-This is Ground connection supply pin of IC.

Pin no. 6-ALERT#-This is a output pin of SM Bus Alert of IC.

Pin no. 7- SDATA- This is a pin of SM Bus Serial Data of IC.

Pin no. 8-SCLK-This is pin of SM Bus Serial Clock of IC.

For working this section +3VS supply is given to pin no.1 of IC U29. Negative supply is given at pin no. 5 of IC U29. Pin no.4 of IC U29 is connected with +3VS supply by resistance R379(10K). Thermal capacitor C402(2200P) is connected with pin no. 2 & 3 of IC (U29), by which sensing the temperature of system and given to pin no. 170 & 169 of EC IC (U20) by pin no.7 and 8 of SM Bus of of IC U29. Monitoring signal of Temperature of system are received to EC IC (U20) through this SM BUS.

23. CPU THERMAL PROTECTION SECTION

Main function of this section is to providing the protection to the Laptop sensing the temperature when CPU becomes more heated, it means when laptop gets more heated then it puts it off. This section is made by using the Duel Computer IC PU6 (LM393) VS supply is given for working this section. For working the CPU thermal Protection section & fixing the invert pin no. 2 of IC PU6, VL supply is given by Divider Circuit, which is known as TM-REF1. Non inverting pin no.3 of IC PU6 is connected with VL Supply by resistance PR85(17.8K). Thermistor PH1 (100K) is ground at this pin. In the normal condition there are more volt at pin no. 3 in comparison of pin no. 2. It means that there is low at pin no.2 and high at pin no.3 & when the value of temperature PH1 of CPU getting low then negative value at pin no. 3. of IC PU6 is increasing . Such a time comes when volt of IC PU6 is low from pin no. 2, due to which high signal sending out from pin no. 1 of IC PU6 is becomes low, due to which Main power ON signal gets low and laptop becomes off.

Testing of System Temperature Sensing & CPU Thermal protection section

We check these sections at that time when there is some problem in the laptop related to the temperature. That means CPU’s temperature is normal but still temperature protection dept is working . For this following components of these sections are to be checked.

Check:- System temperature monitoring IC U29 (ADM1032), IC PU6(LM393), Thermistor PH1, resistance Pr85 etc.

24.HIGH DISK DRIVE (HDD) CONNECTOR DEPT:-

Main function of this section is to attach the laptop with the hard disk drive. By this section HDD storage device is installed in the laptop. For this, in the Acer Travel Mate 2400 laptop, IDE (Integrated Drive Electronics) inter phase JP28 is of 44 pins. For Function the hard disk srive, +5VS supply is given from pin no. 41 & 42 of HDD connector JP28. For signal negative & supply negative , pin no. 2, 19, 22, 24, 26, 30, 40 &43 of JP28 connector is being grounded. For reset the hard disk drive IDE RESET# signal are given to hard disk drive in the form of low by pin no.1 of connector JP28. AND Gate IC U19 (TC75H08Fu) is used for reset the signal. It is 5 pin of IC which pin no. 2 is given +3VS supply & negative supply is given at pin no.3 IDE HRESET# signal are given from pin no. V3 of ICH6M(U13) at input pin no.1 of IC U19 in the form of low. When pin no.1 of IC U19 is getting IDE Hardware reset signal, then IDE_RESET# signal is send out from output pin no. 4 of IC U19 in the form of low, which are given to HDD by pin no. 1 of HDD connector. For PLT reset, pin no.2 of IC U19 receive the PL_RST# signal in the form of low from pin no.R5 of ICH6M U13, due to which IDE_RESET# signal is send out from pin no.4 of IC U19, which is given to pin no. 1 of HDD connector JP28. HDD RESET by pin no. of HDD connector pin no.1.

IDE_LED# is received in the form of low signal at Pin no.39 of HDD connector JP28, to which it is given to pin no. 63of Embedded controller IC U20. +5 VS supply is given at Pin no.39 of LP28 by resistance R224 (100K). For HDD control signal, pin no.21, 23, 25, 27, 29, 31, 33, 34, 35, 36, 37, and 38 of JP28 are used. These pins are attached with ICH6M (U13) chip. Pin no. 17, 15, 13, 11, 9, 7, 5, 3, 4, 6, 10, 12, 14, 16 & 18 of HDD connector JP28 are used for data signal IDE DD0 to IDE DD15. These pins are connected with ICH6M (U13)chip.

25. OPTICAL DISK DRIVE CONNECTOR DEPT:-

Main function of this section is to connecting the optical disk (CD-ROM, CD-Writer, Combo, DVD-ROM, DVD-Writer) driver with the laptop. Optical disk drive are install with this secrtion in the laptop. For this in Acer Travel Mate 2400 laptop, IDE inter phase JP39 is used JP39 connector has 50 pins.

+5VS supply is supplied at pin no. 38, 39, 40, 41 and 42 of optical disk drive connector JP39 for working the optical disk drive. For negative signal and supply negative, pin no. 4, 23, 26, 43, 44, 45, 46, 48 and 49 of JP39 is ground. To reset the optical disk drive, IDE_RESET# is given to optical disk driver by pin no. 5 of optical disk drive connector JP39, in the from of low. For RESET signal AND GATE IC U19 (TC7SH08FU) is used. Ic U19 is 5 pin IC, whose pin no. 5 is supplied +3VS and on pin no.3 negative supply is given IDE_HRESET# signal are given at input pin no.1 of IC U19 from pin no. V3 of ICH6M (U13) in form of low. When IC U19, pin no. 1 receives IDE hardware reset signal then IDE_RESET# signal is send out from output pin no. 4 of IC U19 in the from of low signal, which are given to optical disk drive by pin no.5 of optical disk drive connector JP39. For PLT Reset, PLT_RST# signal are received at pin no.2 of IC U19 from pin no.25 of ICH6M U13 in for form of low, due to which IDE_RESET# signals send out from pin no. 25 of IC U19, which are given to pin no.5 of JP39. Optical disk drive is reset by pin no.5 of optical disk drive connector JP39. CD ROM L, CD ROM R & CD AGND pin of optical Disk drive connector JP39 are connected with pin no. 18, 20 & 19 of IC U40 of Audio Codec Section.

Control& Data signal at that time of optical disk drive connector is connected with ICH6M(U13) chip.

Testing of Heard Disk Drive (HDD) Connector and Optical Disk Drive Connector Section

This dept is checked at that time when in laptop, high disk drive or optical disk drive is not present or drive doesn’t work. For this the following components and supply is checked.

CHECK:- Hard disk drive connector JP28, optical disk drive connector JP39 IC U19, supply 5 VS etc.

26.INTERNAL KEYBOARD CONNECTOR DEPT:-

Main function of this section is to provide the connection of internal key board with Laptop Motherboard. It means do the inter connect each other. By this dept internal key dept internal key board of laptop is attached to motherboard. For this in this internal KBD connector JP4 24 pin is attached. The pins of KsS10-7 and KSo0-15 is attached to Embedded controller IC U20.

27.MOUSE BORD TOUCH PAD section:-

This dept’s work is to providing connection with the motherboard to the touch pad mouse board that means to make them inter connected. By this dept, mouse board’s laptop’s motherboard is attached. For this in this dept mouse board connector JP5, 6 pin is attached. To bring the motherboard in to work connector JP5, of pin no. 5 and 6 is supplied with +5VS and connector JP5 of pin no. 1 and 2. For the give to mouse board, due to which mouse board works in the correct form.

INTERNAL KEY BOARD CONNECTOR AND MOUSE BOARD TOUCH PAD DEPT’S TESTING:-

This dept is checked at that time when laptop’s inter keyboard or touch pad mouse does not work. For this the following components are to be checked.

CHECK:- internal keyboard connector JP4, mouse board connector JP5, embedded controller IC U20 etc.

28. AUDIO SECTION POWER SUPPLY REGULATOR SUPPLY:-

This dept’s work is to regulated +5 VS and then supply the audio dept. In this dept CMOS LDO (LOW DROP OUT) regulator IC U444 (S19182) is used and this dept is made. The regulated supply received from this dept is known by the name +4 VDDA.

The IC U44 (S19182) is attached to this dept, whose description of pins is according to the following pts;

Pin no. 1- CNOISE- This is a pin of noise by pass of IC.

Pin no. 2-DELAY-This is delay pin of power on-reset of IC.

Pin no. 3-GND-This is negative supply pin of IC.

Pin no. 4-VIN-This is an input supply pin of IC.

Pin no. 5-VOUT-This is a voltage output pin of IC.

Pin no. 6-SENSE or ADV- This is a voltage key sense or adjustment pin of IC.

Pin no. 7-ERROR-This is an error pin of IC.

Pin no. 8-SD-This is a shutdown pin of IC.

To make the audio section power supply regulator dept in to work, +5 VS supply coil (L42, L37) is given to pin no. 1 of IC U44 (S19182). Pin no. 8of shutdown is given by +5 VS supply high forever, due to which pin no. 5 of IC U44 regulated volt is out, to which in circuit it known by the name +VDDA. To make the output supply constant, by divider circuit in the form of feedback, output supply IC U44 of pin no. 6 is given, due to which there is no change in the output supply.

29. AUDIO CODEC DEPT:-

This dept’s main work is to convert digital audio data received from ICH6M into analog and then give to analog amplifier and Mic Jack, Line –in-Jack, in input audio analog signal digital gives to ICH6M dept. This dept is known by the name of audio driver dept.

ALC250 chip is used in audio codec division. In this chip DAC (Digital to analog convertor) of 20 bit and 18 bit ADC(analog to digital convert) full duplex AC972.3 stereo audio codec division is made, or three analog lines supports the level stereo input (line_in, CD,AUX) 5bit volume control and two software for analog line level mono input phone in or PCB, is supported for selectable MIC input, for +6/12/20/30 Db boost pre amplifier, audio playback DVD for double sampling rate (96KHz). This chip is in 48 pin TQFP package.

The description of Audio Codec IC U40 pins are as follows:-

Pin no.1-DVDD1-it is the +3VS supply input pin of digital part.

Pin no. 2-XTL.IN-this is the input pin of crystal.

Pin no. 3-XTL_OUT-this is the out pin of crystal.

Pin no. 4-DVSS1-this is the ground pin of digital part.

Pin no. 5-SDATA_OUT-this is the serial TDM input pin of AC97 controller.

Pin no. 6.-BIT_CLK-this is the output pin of 12.288 MHz bit clock.

Pin no. 7-DVSS2-this is the grnd pin of digital part.

Pin no. 8-SDATA_IN-this is the output pin of AC97 codec serial TDM.

Pin no. 9-DVDD2-it is the +3VS supply input pin of digital part.

Pin no. 10-SYNC-this is the input pin of SYNC sample (48KHz)

Pin no. 11-RESET#-this is the hardware reset pin of AC 97.

Pin no. 12-PC_BEEP-this the input pin of laptop beep signal.

Pin no. 13-PHONE-this is the input pin of speaker phone.

Pin no. 14-AUX_L-this is the i/o pin of AUX left channel.

Pin no. 15-AUX_R-this is the i/o pin of AUX right channel.

Pin no. 16-JD2-this is the input pin of jack detect 2.

Pin no. 17-JD1-this is the input pin of jack detect1.

Pin no. 18-CD_L-this is the input pin of CD audio left channel.

Pin no. 19-CD_GND-this the gnd pin of CD analog audio.

Pin no. 20-CD_R-this is the input pin of CD audio right channel.

Pin no. 21-MIC1-input pin of first mic.

Pin no. 22-MIC2-input of second mic.

Pin no. 23-LINE_IN_L-input pin of left channel line.

Pin no. 24-LINE_IN_R-input pin of right channel line.

Pin no. 25-AVDD1-this is the input pin of +ve supply of analog part.

Pin no. 26-AVSS1-this is the input of –ve supply of analog part.

Pin no. 27-VREF-this is the pin related to reference volt part.

Pin no. 28-VREF OUT-output pin of reference volt part.

Pin no. 29-AFILT1- this is the pin of Filter 1 of analog to digital convert part.

Pin no. 30-AFILT2- this is the pin of Filter 2 of analog to digital convert part.

Pin no. 31-NC-this is the pin pin of Not Connection.

Pin no. 32-DCVOL-input pin of DC voltage volume control.

Pin no. 33-VREFOUT2-output pin of secondary reference voltage.

Pin no. 34-VAUX-input pin of auxiliary power volt.

Pin no. 35-LINE_OUT_L-output pin of left channel line out.

Pin no. 36-LINE_OUT-R-outputpin of right channel line out.

Pin no. 37-MONO_OUT/VREF OUT3-output pin of mono out/3^rd reference volt.

Pin no. 38-AVDD2-this is the input pin of +ve supply 2 of analog part.

Pin no. 39-HP_OUT_R-pin of left of right channel headphone out.

Pin no. 40-NC-Not connection pin.

Pin no. 41-HP_OUT_R-pin of right channel headphone out.

Pin no. 42-AVSS2-this is the input pin of –ve supply 2 of analog part.

Pin no. 43-SCK-input pin of serial clock bit.

Pin no. 44-SDA-i/o pin of serial data.

Pin no. 45-NC-pin of Not Connection.

Pin no. 46-XTLSEL-input pin of external 14.318 MHz clock source.

Pin no. 47-SPDIF1/EAPD-i/o pin of S/PDIF input and external amplifier power down control.

Pin no. 48-SPDIF0-out pin of S/PDIF.

Working system of Audio Codec

+VDDA supply is given to supply pin no.25 and 38 of Audio Codec IC U40 (ALC250) of analog section by the coil L36 from Audio section power supply regulator part and +3VS is given at supply pin no.1 and 9 of Audio Codec IC U40(ALC250) to Digital Section. Negative Supply is given to the Analog section by pin no. 26 and 42 of IC U40. Negative supply is given to the Digital section by pin no.4 & 7 of IC U40. When supply of Analog & digital is given to IC U40 then reference volt is send out from reference volt section made within the IC, which are send out from pin no. 28 of IC U40, which are known as +AUD_VREF. Audio Codec Rest signal are given to pin no. A10 of South bridge (ICH6M) U13 in the form of low for hardware reset of IC U40, due which IC U40 becomes rest. 14.318 MHz Clock signal is given at pin no. 2 of Audio Codec IC U40 from pin no. 53 of clock generator IC U33. This IC is Plug-in-play IC. For the working of IC according to the system, driver of ALC250 is installed according to the system then Audio Codec Sync and Audio Codec serial data are given on IC U40 pin no.10 and 5 by ICH6M pin no. B9 and C9. Left and right channel audio out from IC U40 pin no. 35 and 36 by connecting the digital audio signal in the analog signal, which is given to the audio amplifier IC U42 pin no.7 and 2. The laptop beep sound signal obtain from transistor Q20’s collector given to IC U40 pin no.12 by which sound is obtain from laptop speaker. In this way MIC, internal CD L-R, and line L-R signals are given at different pins of Codec IC U40.The signal which is selected by the IC that audio signals is given to audio amplifier section.

30.AUDIO AMPLIFIER DIVISION:-

The main work of this division is to amplify pre audio signal obtain from Audio Codec and given to the laptop speaker. This division is made by using the audio amplifier U41 (APA2066).

In this division audio amplifier IC U41 (APA2066) is of 16 pin IC. Descriptions of following pin are under as follows:-

Pin no.1-R by Pass-this is related to right channel internal mild supply base voltage driver.

Pin no. 2-RIN-pin of right channel line.

Pin no. 3-ROUT+-output pin of right channel’s +ve speaker terminal.

Pin no.4, 5 and 13-GND-gnd connection pin of circuit.

Pin no. 6-LOUT+-output pin of left channel’s +ve speaker terminal.

Pin no. 7-LIN-pin of left channel line.

Pin no. 8-LBYPASS-this is related to left channel internal mild supply base voltage driver.

Pin no. 9-LVDD-input pin of left channel line.

Pin no. 10-SHUTDOWN-input pin of shutdown mode.

Pin no. 11-LOUT-output pin of left channels-ve speaker terminal.

Pin no. 12-MUTE-input pin of mutr control signal.

Pin no. 14-SE/BTL#-input pin of mode control signal.

Pin no. 15-ROUT-output pin of right channels-ve speaker terminal.

Pin no. 16-RVDD-input pin of right channel’s +ve speaker terminal.

For the working of Audio Amplifier division supply of +5VAMP audio section regulator division is give by IC U41 pin no. 9 and 16 and negative supply on pin no. 4, 5 and 13. When on left and right pin of IC U41 audio signal audio codec division got on IC U40 pin no. 35 and 36 then IC U41 amplify and out from pin no. 3, 6, 11 and 15 which is out from internal connector JP42 PIN NO. 1, 2, 3 and 4 by coil L43, L44, L45 and L46 and resistance r634, R636, R635 and R637. Audio signal obtain from speaker connector JP42 given to it, by which we listen sound from speaker but for shutdown audio amplifier IC, from EC IC U20 pin no.40 given to IC U41 pin no. 10 in the form of EC-Mute signal high. When we obtain high on this pin, then IC U41 is shutdown means we can’t get sound speaker.

To mute IC U41 amplifier division by EC IC U20 pin no. 42, AMP_MUTE# signal is given to IC U41 pin no. 12 In the form of high. When we obtain high on IC U41 pin no. 12 then the IC amplifier division is mute means audio amplifier division off. Select signal of NBA Plug Mode to IC U41 pin no. 14 is obtain from audio codec division of IC U40 pin no.17.

31. High Phone MIC Jack Division:-

(1) High Phone Jack Division:- Work this division is out audio signal given by audio amplifier division by headphone jackpot and giving information of headphone plug in to audio amplifier. In this division 2 input and gate IC U25(TC7SH32FU mosfet Q37 (2N7002) Q38(ND5352) and headphone jack (JP20) are used to build this division.

Headphone jack division 10pin head phone jack is fix, in which 1, 6 and 10 is loose. Left and right channel audio channel audio signal is given by pin no.2 and 3 on LCR circuit. +5VAMP supply is given on OR Gate IC (U25) pin no. 5 for NBA_PLUG Mode and pin no. 3 is grnd. IC U25 input pin no. 1 is grnd by resistance +5VALWP supply is connected.

Mosfet Q37 source is ground. When in JP40 connector head phone (NBA PLUG) is not connected then supply of +5VAMP obtain at mosfet Q37 and Q38 gate by the resistance R316(10K).

By which mosfet Q37 is on because mosfet Q38 is N-channel mosfet, therefore mosfet Q38 is off because mosfet Q38 is P-channel mosfet, by which on IC U25 pin no.2 obtain low by mosfet Q37 drain ,which we get low out on IC pin no. 4 and when NBA is plug then we get low at mosfet Q37 gate, by which mosfet Q37 is off and get high on IC U25 pin no.2, which we get high on IC output pin 4, which NBA_PLUG signal given to audio amplifier IC41 pin no. 14 in form of high.

(2) MIC JACK DIVISION:- Main work of division obtain is audio signal from MIC by control and give to audio codec division and give power supply for work to MIC. This division is use to build by using Mic Jack (JP41, MIC) and LCR circuit. For the working of Mic jack division obtain from IC U40 supply of AUD_VREF by resistance R350, R351 (2.2K*2) given to left and right channel mic.

Mic jack is of JP416, whose pin no. 1 when ground pin no. 2 left mic pin no. 3 right mic pin no. 4 NBA PLUG Sense and pin no. 5 is NC. Pin no. 1 from internal mic received audio signal jack JP41’s pin no. 6 gets out through pin no. 2, which is given to audio Kodak IC U40’s pin no. 23 by coil (L40) resistance R327 (6.8K) capacitor C371(1MF).

Right channel of pin no. 3 of signal jack of external mic and from pin no. 2 left channel’s mic audio signal is received, which is given to pin no. 23 and 24 of IV U40 of audio Kodak by LCR circuit.

To sense the plug in of external mic, mosfet Q42 gets on and then low volts out from source to drain, because of which pin no.90 and U40 of IC U20 is low received on pin no. 16, the one who senses this, that mic piug is not done and the moment mic plug is done, ten on the gate of mosfet Q42 is low received, due to which mosfet Q42 gets off and low is stopped getting from drain. Drain’s pin gets high, which is send to pin no. 16 of U40 and pin no. 90 of U20 in the name of NBA_PLUG_M, due to which is sensed that the mic plug is in.

THE TESTING OF AUDIO SECTION POWER SUPPLY REGULATOR, AUDIO AMPLIFIER, HEAD PHONE AND MIC JACK DEPT:-

These dept are checked in a situation, when some audio related problems in laptop occurs like improper audio, head phone not working, mike not working, not getting the sound from internal speaker. In this situation, the various components supply and signal in these dept are checked.

CHECK:-Audio section power regulator IC U44(S19182), coil L42, L37, audio Kodak chip U40 (LC 250), coil L36, audio amplifier IC U41(APA 2066), speaker connecter JP42, head phone jack JP40, mike jack J41, mosfet Q42, coil L43, L44, L45, L46, L35, L38, L41, supply +AVDD_AC97, +VDAA, +5 VAMP, +AUD_VRF, signal ICH_AC_RST#, ICH_AC_SYNC, ICH_AC_SDOUT, LINE_OUTL, LINE_OUTER<EC_MUTE etc.

32.Beep Sound Controller Section

The work of this dept is to control the beep signal received from the embedded control, PCMC1A controller and south bridge dept and also to pre-amplify and then to send it to the audio Kodak dept. This dept is made by using the inverter ICU34 (SN741VC144AP) and the transistor Q20 (2SC 2411K).

The positive supply of 3V on pin no. 14 and pin no. 7 of ICU34 is supplied to make the beep sound signal controller dept work.

The pre-amplifier transistor Q20(2SC2421K) is used in this dept and the +VDD supply on the collector is given through the resistance R326, R321 (0KX₂). This dept uses the 3 gates of the inverter IC U34. All the inputs of the 3 gates are on pin no. 1, 2, 3 and 5 are given to beep#, PCM-SPK# and SB_SPKR signals. The beep signal obtained from the output of the gate is given at the base of the transistor through the capacitor and resistances. The beep signal obtained from the transistor base is amplified and then signal is out through the collector, which is given to the audio Kodak IC U40 pin no. 2 through the capacitor C367 (1 MF), due to which the sound of the beep signal is obtained from the speaker of the laptop

The testing of beep sound signal controller dept:-

The dept is checked in a situation when during error in the laptop, the error beep sound is not received through the speaker. That is why the following components are checked in this dept.

Check: Inverter IC U34 (SN74 LVC14), transistor Q20, resistance R326, R321, supply +VDDA etc.

33. USB PORT POWER SUPPLY CONTROLLER DEPT:

The main work of this dept is to control and supply the +5VALW of USB port which is in laptop. In this dept power switch IC U16, (G528) and U26(RT9702A) and transistor Q22 (DTC115EkA) is used.

USB Port power supply controller dept’s working and its briefings: In Acer Travel Mate 2400 laptop, 3 USB ports are attached, 2 on the left side and one on the rear side.

(i)Left side USB port: Left side USB port is fixed in JP24 and JP25. Both these ports’ power supply is controlled by power switch IC U16 (G528), whereas rear side USB port JP13’s supply is controlled by power switch IC U26.

For left side USB port’s supply power switch IC (U16) is of 8 pin IC, of which the details are according to the following points.

Pin no. 1-GND-This is negative signal pin of IC.

Pin no. 2,3-IN-This is the input supply of IC.

Pin no. 4-EN#-This is the switch enable input pin of IC.

Pin no. 5-FLG-Thus is the output pin of fault flag of IC.

Pin no. 6, 7 and 8-This is the switch of output pin of IC.

To give the supply on the left side of USB port, +5VALW supply is provided on the pin no. 2 and 3. When the YSON signal from the pin no. 148 of ECIC V20 in the form of high is sent to the transistor Q22 base, then transistor Q22 switches on and then makes the power switch ICU 16 pin no. 4 low, due to which the ICU 18 switch gets enable and from ICU 16 pin no. 6, 7 and 8 and USB port supply volt comes out named as +USB BS, which are provided to pin no. 1 of JP24 and JP25.

Negative supply is provided on pin no. 4 of the USB port JP24 and JP25 or we can say that this is grounded in the circuit.

Where there is a fault in the left side USB port, then error signal in the from of low generates out on pin no. 5 of ICU 16, which is provided on pin no.B26 and C23 of IC H6M chip. To make the pin no. 6 of ICU 16 HIGH, a supply resistance of +3 VALW is provided through the resistance R178(10K). The data pin no. 2 and 3 of the USB port JP24 is connected to the pin no. E17 and D17 of IC H6M chip (U13). The data pin no. 2 and 3 of the USB port JP24 is connected to the pin no. D19 and D19 of IC H6M chip (U13).

(ii)Rear side USB Port : To give the supply to the rear side, power switch IC U26 (RT9702) is attached. This is a 5 pin IC, of which description is according to the following points:

Pin no. 1-CE-This is a pin of chip enable of IC.

Pin no. 2-GND-This is a negative supply pin of IC.

Pin no. 3-FLG-This is an output pin of fault flag of IC.

Pin no. 4-VIN-This is a pin of supply input of IC.

Pin no. 5-VOUT-This is a volt output pin of switch of IC.

To give the supply to the rear side USB port, on pin no. 4 of IC U26, +5VALW is supplied. When from pin no. 148 of EC IC U20 SYSON signal is received in the form of high signal from pin no. 1 off IC U26 then from pin no.5 of IC U26, USB port supply is out, to which is also known as by the name +USB AS. To the rear side of this supply is given to pin no. 1 of USB port JP13. With the help of pin no. 4 of JP13 negative supply is given. Pin no. 5, 6, 7 and 8 of USB port JP13 ground. When there is a fault of any type in the rear side of the supply of USB port then pin no. 3 of IC U26 is out in the form of flag signal low from error signal, which are sent to pin no. C24 of ICH6M(U13. The data pin no. 2 and 3 of USB port JP13 on the rear side is attached to pin no. C21 and D21 of ICH6M (U13)

THE TESTING OF USB PORT SIGNAL CONTROLLER DEPT:

The main work of this dept is to control the +5VALW supply to USB port in the laptop and then to check CHECK: In this dept the power switch IC U16 (G528), U26 (RT9702A), Left side USB port Rear side USB, supply +USB_BS, +USB_AS, signal SYSON#, SYSON etc.

34.LCD PANAL POWER AND CONNECTOR:

The work of this dept is to provide power to the LCD panel and for display control and provide data signal that means the connection of LCD panel a connector of 40 pins connected in this dept. The display attached with the help of this connector, inverter board’s supply and control is given. For the inverter pin no. 1, 2, 21, 22 and 23 of JP16 is taken into work.

To the inverter board from the battery charging and power selector received supply of B+, is given with the help of pin no.1 and 2 of connector JP16. To control the brightness of the display panel, pin no. 21 of connector JP16 is given to DAC_BRIG signal inverter board. To the inverter board, INVT_PWN control signal is given by the help of pin no. 22 of JP16. DAC_BRIG and INVT_PWM control signal embedded controller IC U20’s pin no. 99 and 32 is given to it. To put the inverter on/off, pin no. 23 of JP16 is taken into work. For this pin no. 28 of embedded controller IC U20 to BKOFF# signal low in its form, pin no. 23 of JP16 connector by diode D3 (RB751) by it. Display of signal inverter board received on pin no. 23 of JP16 connector is given to on/off.

To control the power supply of LCD panel, in this dept mosfet Q6 (S12301), Q7 (2N7002) and Q43 (BSS138) is attached, which is controlled by pin no F26 of GMCH. On the source of mosfet Q26 of power control, +3 V is supplied. To the gate of Q7 mosfet Q43’s drain and to the gate of Q7 it is given. On the drain of Q6, by resistance R63 (1K )+3V is supplied and drain of Q6, by resistance R61(300E) the supply given to the LCD panel is attached. When on the gate of Q43, GMCH to enable in the from of high VDD signal, on the gate of mosfet Q43 is received then by mosfet gate on and negative volt resistance R624, it gives to the gate of mosfet Q26, from which mosfet Q6 gets on and then drain to source +3 V supply is out, which is known by name +LCDVDD. This +LCDVDD supply is given to the LCD panel by pin no. 24, 25 and 26 of connector JP16 and when enables from GMCH chip VDD signal is not received then mosfet Q7, positive volt is received then after getting on mosfet Q7, the supply of LCD panel discharges immediately, due to which the supply stops for LCD panel. LCD panel is differently supplied +3 V by pin no. 4 of JP16. Pin no. 7, 10, 13, 16, 19, 27, 30, 33, 36 and 39 of connector JP16are ground. By these pins LCD panel and inverter dept is supplied with negative supply and signal ground is received.

The signal of image Data clock and control signal are out in the LVDS format from the GMCH chip division for this two channels are used in the LVDS division in first channel TZOUT0+ to TZOUT2+ and TZOUT0- to TZOUT2- is given and in second channel TXOUT+ to TXOUT2+ and TXOUT0 to TXOUT2- LVDS signal iis given and in second is given in the two channel, different clock is given connector JP 16 is for pin no. 20 of LC-ID which is connected to pin no. 95 of IC H6M U19 the pin no. 3 and pin no. 4 is left NC.

LCD PANEL POWER AND CONNECTOR DIVISION TESTING:-

This division is checked when, the external display port is receiving the display, but the LCD screen is not receiving the display so the following components are checked at this division:-

CHECK:- MOSFET Q6, MOSFET Q43, MOSFET Q7, resistance R624, LCD panel connector JP 16, supply +LCDDVVD, B+, +3VS , signal DAV_VRIG, INVT_PWM, GMCH_ENVDD, etc.

35. INVERTER PART:

The main working of this portion is to given supply to the CCFL (cold cathode fluorescent lamp) of LCD panel, which provides brighter images on the screen. To achieve that, this portion is made up of CCFL, Piezeo electric transformer, CCFL diver IC.

1.CCFL: In Laptops, CCFL gives light of mercury color. The size of this lamp ranges from 2.5” up to all size. This lamp gives the light according to its watt rating. Luminance of 1 watt CCFL is 67. As the Luminance of 1 watt CCFL is 67. As the Luminance of the lamp increases, the light output also increases. The unit of light is Luminance, which is generally measured in Candle.

1 Candle= 1 Luminance

CCFL has ON time life of 25000-45000 and length and width of the lamp should be same while changing it.

2. Piezo electric transformer:- Piezo electric transformer is used in the CCFL card of the Laptop. This transformer is lighter in weight and slimmer in size and is like a S.M. transformer. In this transformer, a coating of wire wound ceramic material is done over the winding in this transformer, by which harmonic signals (noise) from it, is 0%. There is no emf out in this transformer and it doesn’t produce heat. It doesn’t get short. It always remains open. It does the switching of high frequency. A non-flammable material is used in this transformer; due to this it doesn’t get burned. It doesn’t affect an electric device near it while turning ON the transformer.

3. Circuit of inverter portion-CCFL IC U1 (MP1010B) is a 20 IC. Pin no. 7 and 14 of IC U1 is connected from pin no. 1 and 2 of connector of inverter board respectively to make IC work.

Pin no. 20 of IC U1 is negative supply pin of analog part and is grounded. Pin no. 9 and 12 are the negative supply pin of switching part and is also grounded. Left and right output pin of power switching are connected to two ends of primary winding of piezo transformer T1. Pin no. 10 and 11 of IC U1 are the Boost left and right input which are connected to output pin via capacitor C12 and C7 respectively. Pin no. 4 of inverter board connector is connected as a display off low signal and pin no.5 of inverter board connector is connected as a display ON high signal. When pin no. 5 gets high signal, the IC gets enabled and when it gets low signal, the IC gets disabled. Pin no. 3 of connector is connected to pin no. 4 of IC U7 to give inverter PWM control signal, from which the PWM pulse get controlled and the brightness of the display screen is controlled. By the pin no. 5 of connector, the brightness signal are sent to pin no. 1 of IC U1 by which the brightness of the LCD is controlled the +Ve supply is given to the pin no. 7, pin no.14 of IC and- Ve supply is given to pin no. 20, pin no. 9, pin no. 12 of IC U1 then reference volt is out from pin no.15 of IC U1 which is given to the pin no. 3 via resistance of IC the brightness signal are out as high from pin no. 1 of IC in the form of INVT PWM high signal on the high pin no. 4 on the pin no. 5 by the connector of the IC then AC pulse are out from the pin no. 8, pin no. 13 of IC U1 which are given to primary winding of transformer T1 in the pizo transformer, there is induction in the primary winding, which is received in the secondary winding if transformer of T1 as this is step up transformer, so the value received in the secondary winding is more which is given to the CCF of LCD by the connector by the pin no.1 & pin no. 2 to control the out put supply, the supply at SW is given at feed back pin no. 19 of IC U1 to control the output current, the volt from pin no. 1 of connector CN is given to the pin no. 2 of IC U1 to control the over voltage, by the capacitor C9 & C10 , a divider circuit is made and is given to pin no. 18 of IC U1.

TESTING OF INVERTOR DIVISION:-

This division is checked when, the LAPTON GETS on, but the display on the LAPTOP is not seen and the display on external monitor is seen, so the following supply, component and signal are check:-

CHECK:- IC U1, PIZO transformer, CCFL connector CN1, CCFL, flue F1, supply B+ signal VRIG, DISP OFF #HIGH, INVT PWM etc.

36.EXTERNAL DISPLAY PORT DIVISION:-

The work of this division is to obtain laptop display by another display device, means obtain image by CRT monitor, LCD monitor or projector. This division is build by using external display port (VGA port), signal bus buffer gate IC U27, U28 (SN74AHCT1G125*2) and mosfet Q3 Q4 (2N7002).

For the working of this division +5VS supply is obtained from diode D18 (RB411D), which is known as +R_CRT_VCC supply, +R_CRT_VCC supply is given to circuit by Fuse F1, which is known as +CRT_VCC supply.

+CRT_VCC supply is given to signal is given bus buffer gate IC U27 and U28 pin no. 5 in this division. Negative supply is given by IC U27 and U28 pin no. 3.

For digital display data channel clock and data signal mosfet Q3 and Q4 is used in this division. CRT Vertical Sync Signal is obtain from GMCH division chipset U31 pin no. G21 by resistance R372 (39E) on IC U27 input pin no.2 IC U27 amplify the Horizontal Sync signal and out from output pin no. 4, which given by coil L3 to VGA PORT pin no. 13. For Vertical Sync singal CRT Vertical Sync signal is obtain from GMCH chipset U31 pin no. H21 by resistance R378 (39E) on IC U28 input pin no. 2. IC U28 amplifier Vertical Sync signal and out fr4om output pin no. 4, when given by coil L1 to VGAPORT pin no. 14.

For the display color signal GMCH chipset U31 pin no. A19 to Red pin no. C20 to Green and pin no. C21 to Blue signal are obtain to this division, which out from VGAPORT JP3 pin no. 1, 2 and 3 by coil L5 and L2.

For digital data channel clock and data signal mosfet Q3 and Q4 is used in this division. +CRT_VCC supply given to mosfet’s drain by resistance R371, R374 (4.7K*2) Q3 mosfet is used for data and Q4 mosfet for clock Q3’s drain is connected to VGA PORT JP3 pin no. 12 and Q3’s drain is connected to VGA PORT JP3 pin no. 15.

MOSFET Q3 and Q4 are always ON the positive supply voltage 3V and 2.5V respectively. Resistor R41(0E) is connected between source of MOSFET Q3 and pin no. E23 of CRT data of GMCH chipset. Resistor R47(0E) is connected between source of MOSFET Q4 and pin no. E24 of signal.

Testing Of External Display Port:-

We check this part at that time, when the Laptop working properly, means display are received on the LCD screen, but when external monitor connected there are no display on the external monitor. For this in this part following component and supply are tested.

Test:-External display port JP3, IC U27, Coil L1, L2, L4, L5, MOSFET Q3, MOSFET Q4, Diode D18, D19, D20, D21, Supply +CRT_Vcc etc.

37. MODERN DAUGHTER CARD CONNECTOR DIVISION:-

The main working for this section is to connect modem daughter card, For this JP14 20 pin modem daughter card connector is used in this division. For giving supply to modem daughter card, pin no. 6 of modem daughter card is given +3V supply.

For giving –V supply to the modem daughter card , pin no. 5, pin no. 8, pin no. 10 is grounded the audio codec serial data is on pin no. 3 of connector JP 14 by the chip ICH chip U13 in modem daughter card to reset the modem daughter card, the pin no. 11 is used of the connector JP 14 at this pin audio codec sync signal are got from pin no. 7 of ICH U13 the audio codec sync signal from the pin no. B9 of ICH U 13 is received on the pin no. 7 of JP 14 the out serial data from the modem daughter card is out from pin no. 9 of JP 14 which are given to the pin no. F10 of ICH 6MU 13 by a res R13. ICH audio codec bit clock signal are out from the pin no. 12 of JP 14 connector which are given to pin no. C 10 of ICH 6M U 13.

MODEM DAUGHTER CARD CONNECTOR DIVISION TESTING:-

This division is checked when the modem daughter card does not works in the laptop the following component are checked at this situation.

CHECK:- modem daughter card connector, JP 14, supply +3 V ICH_ACRST# etc.

38. BLUE TOOTH INTERFACE SECTION:-

The main working of this division is to interfacing of blue tooth card for this work, there are 8 pin connector JP 1 and MOSFET Q31 for blue tooth interface.

+3 VALW supply is given to the source of MOSFET Q31 for making blue tooth card to work the blue tooth on signal in the form of low are received at gate Q 31 MOSFET by the pin no. 119 of EC IC U20. By which the MOSFET gets on and it flows +volt from source to drain which is known as BT_VCC supply the blue tooth card supply the blue tooth card supply is given by pin no. 1 of BT connector JP 1 as BT_VCC supply.

For +Ve and –Ve supply in USB 20, pin no. 3 & pin no. 4 are used of connector JP 1 which are connected to pin no. A16 & pin no. B16 of ICH 6M U13, pin no. 6 & pin no. 7 of wireless LAN Bluetooth data and LAN Bluetooth clock signal are connected to pin no. 43 & pin no. 36 of JP 35.

Blue Tooth Interface Section Testing:-

This division is checked when the blue tooth card of LAPTOP is not working then the following components are checked.

CHECK:-

Blue tooth connector JP1, MOSFET Q31, supply BT_VCC, SIGNALBT_ON# etc.

39. PC CARD BUS SLOT DIVISION :-

The main work of this division is to control PC card interface. The design of PC card is done for computer memory. But used for control external device of laptop. Like-Network Card Modem and Conditional Access module etc. In this section PCMCIA (Personal Computer Memory Card International Association) power controller IC U36 (CP2211) and card bus slot JP7 are used to build this section. PC card bus slot is 68 pin slot, S1_VCC supply is given by PCMCIA power switch control IC U36 on VCC supply pin no. 17 and 51.

S1_VPP supply is signal of PC Card Bus Slot JP7 are controlled by PCMCIA controller chip U39. For the power supply PCMCIA power switch controller IC U36 (CP2211) is of 16 pin. Description of these pins is as follows:

Pin no. 1-VCCD0-input pinj of AVCC logic voltage control.

Pin no.-2-VCCD1- input pin of AVCC logic input voltage control.

Pin no.-3, 4-3.3 V- input pin of +3.3V VCC.

Pin no.-5, 6-5 V- input pin of card power and chip power of +5V VCC. Pin no.-7-GND-pin of grnd.

Pin no.-8-OC-output pin of over current of logic label.

Pin no.-9-12V-input pin of over current of logic label.

Pin no.-10-AVPP-this the switched output pin of card power delivers supply 0v, 3.3v and 5V.

Pin no.-11, 12 and 13-this switched output pin of card power delivers supply 0v, 3.3v and 5V.

Pin no.- 14-VPPD1-input pin of AVPP logic output voltage control.

Pin no.- 15- VPPD1-input pin of AVPP logic output voltage control.

Pin no.- 16-SHDN-input pin of IC logic input of shutdown.

For the working of this division +5VS supply and +3VS supply is given on pin no.5, 6 and pin no. 3, 4 of IC U36 respectively. Pin no. 7 is ground. Pin no. 8 and 9 is not in use. When logic voltage control select signal from PCMCIA controller chip is supply volt out from IC U36 pin no.10, 11, 12 and 13, which is given to pin no. 17, 51, 18 and 52 by the name +S1_VCC and +S1_VPP of PC card bus slot.

For the working of logic voltage select input pin high is given by resistance R562 (10K) to +3VS.

Testing of PC Card Bus Slot Division:-

When we connected PCMCIA card then we will check the division and the card is not working the following components.

CHECK:-PCMCIA power controller IC U36 (CP2211), PC Card bus slot JP7, +5VS +3VS, supply+S1, +S1_VCC, +S1_VPP, signal VCCD0#, VCCDE1#, VPPD0, VPPD1 etc.

39.NETWORK AND MODEM JACK SECTION:-

The main work of this division is to provide Interfacing Port to laptop for network and modem, by which we cannot laptop with internet and network. For this, in this division for network RJ45 and for modem RJ11 port JP19 and magnetic module T1 (24ST0023) is used to build this division.

For the working of this division +3VALW supply is control by mosfet Q11 (S12301DS). +3V_LAN supply is generate. EN_WOL# signal is given to mosfet from EC IC U20 pin no. 75.

RL45 and RJ11 are port of JP19 14, in which pin no. 1 and 2 Yellow LED Id crystal. Activity is used. On anode of yellow LED+3V_LAN is given by resistance R90(300E).
Cathode of yellow LED _ACTIVITY signal in low form through RP18 (0E) it is used for data transfer or receiver through pin number 3 to 10 of JP19, which is connected with LAN controller chip U8 by magnetic modules T1. Magnetic module T1 get +2.5V_LAN supply through transistor Q5 fitted on controller system, which is given to 1, 4, 7 and 10.

For LAN link green led is fit in JP19, anode on which +3V_LAB supply is given through resistance R133 (00E). Cathode of green LED gets LAN link# low signal through resistance RP18.

For modem 13 & 14 of RJ pot used from 13 of JP 19, it is given to modem daughter card to telephone line.

NETWORK AND MODEM JACK DIVISION TESTING:-

This division is checked when the LAN port or the modem jack in the LAPTOP is not working then the following component and supply are checked.

CHECK:- Network and modem jack JP 19, magnetic module, modem connector JP23, resistance PR10, PR20, PR21, PR22, power supply +3V_LAN, +2.5V_LAN etc.

CHAPTER-5

LCD PANEL

LCD panel used in laptop, is a such type of output display device which made as a different unit. When you work on laptop or play games then this displays the text and graphic image and immediately provides feedback. Laptop uses the liquid crystal display these days to consume less energy and same design, generally laptop have LCD technology (which are known as flat panel or flat screen).

Liquid crystal was discovered by Fredick Rinitichuer of Austria in year 1888. It is a organic material , it is in shape of crystal. These have both soild and liquid properties. But at room temperature they are found as liquid crystal depends upon voltage and current they are also affected by pressure and heat.

In nature they are found in 3 forms.

1. Solid (crystalline)

2. Liquid crystal (mesofaze)

3. Liquid (isotropic)

1. Solid(crystalline): Some crystals are found in form of soild state. These are not affected by normal temperature, means that temperature of environment and humidity does not effect the atom of this due to this it is known as crystalline.

2. Lequid crystal (mesofaze):- when a solid liquid crystal is heated, then its atoms are changes and there shaped is also changes. This type of liquid crystal is known as mezofaze liquid crystal. There are neither liquid nor crystal. It is in from of both crystals.

3. Liquid (isotopic):- When temperature or pressure is given on liquid crystal then there change in the state or structure, that change in state of liquid crystal is called isotopic liquid.

All the three state are shown in the following figure:-

Working Procedure of LCD:

To understand the working of LCD the light of back light rays are passing through LCD. Light source is set always behind the LCD, LED or fluorescent technology is used for back light. In this method the rays of light pass out by light polarizer such type that this polarized light beam is passed through liquid crystal matrix, which confirm that pixel must be ON or OFF.

If pixel is the ON position then liquid crystal cell activated in the form of electrical and liquid crystal is aligned in signal direction. In this position there will be no change in the light position. If pixel are in the OFF position then electric field will be remove and particle will be movable in liquid.

In this position the pixel of that display in passing through liquid crystal.

Now we explaining the working procedure of passive and active crystal display and its main production steps:-

PASSIVE MATRIX LCDs:-

In passive matrix type LCD switching drive is not available. There are frame for each pixel, connected in it and a address of that pixel by which the passive matrix LCD have many layer. The main part of it is the two glass plates, which are connected by seal. Polarized is fixed for coming the polarized light in the signal direction on the first glass plate. Now light is passed out from the front glass plate. One layer of Indium Tin Oxide (ITO) is used in the form of electrodes. Passivation layer is also known as heard coat layer, which is based on SiO_x and fixed on the ITO (Indium Tim Oxide) in the form aligened liquid crystal fluid.

Liquid crystal is also optically active and rotate in the polarization direction of incoming light. The width of this layer is obtained by spacer, which maintains a fix distance between two glass plates. When there is no any electric potential at the rear part of glass from the front part of glass then as polarized passed out from liquid crystal layer then it is rotate in the 90⁰. When electric potential is not connected from one plate to another plate then light is not be rotate. After passing out from the liquid crystal, light is passed out by second polyamide layer, second hard coat layer, ITO Electrode & rear glass. When it reaches at rear polarizer then either it is transmit by it or absorbed by it. It depends on it that rotate 90⁰ or not.

ACTIVE MATRIX LCDS:-

The use of active matrix technology is for thin film transistors (TFT) or amorphous or poly crystalline silicon on LCD glass plate. While it is easy to use amorphous silicon TFT’s and now a days it is used for large display. Poly silicon TFT’s show good performance but it requires more temperature. They only used in tube furnace and poly silicon technology are used for small display manufacture.

Active matrix is also known as LCD switch device. In this integrated switching device is used in the form of transistor, which is made up of thin films medium. For this also knowledge this film transistor.

TFT

Full name of TFT is “thin film transistor “. It has a tiny transistor which is made with every transparent pixel electrode of TFT LCD panel. These are made at the glass panel behind the LCD panel which has gate, drain source, data and gate line.TFT gate display data signal by the data line and ON/OFF signal by the gate line. Three sub pixels (RGB) are made for every sub pixel, which can be understand by following diagram-

COLOR FILTER

In color display, after passing the light through liquid crystal matrix, it passed through color filter. This display the light according to RGB color of color filter. Color filter is fixed near to upper glass. Three different pixels of red, blue and green are attached for every pixel. Black color pixel is in the middle of color pixel, which increases the contrest of picture. After the light beam through color filter, it goes to other polarize to sharp the position of image. Then image is prepared for view.

Color filter is made for making the color display in TFTLCD. Main work of it is that convert the polarized light according to signal. These are made in upper glass according to pixel electrode of lower glass panel which are of red, green and blue color and known as Delta Array, Strip Array and Mosaic array and can be understand by following diagram-

Three main technologies are used in TFTLCD’ amorfous silicon’ (a-Si)’, ‘polycristlin silicon’ (p-Si)’ and ‘signale crystal silicon’(x-Si).

Silicon transistor matrix in TFT is made of amorfous. Amorfous silicon TFTLCD’s color is good and good work ability. Because a-Si are of low nature (area/voltage second). A capacitor is always used with every pixel of it. A-Si production process gets only four basic lithographic steps.

Even line generation is correct and it work at low voltage a-Si TFT technology has some weak points too. To remove these, we have new technology of the TFT display which is known polycrystalline silicon (p-Si).

Polycrystalline silicon (p-Si) is similar to amorfous technology. Different is that TFT display is more effective in it And its manufacturing is more costly p-Si TFT technology is used in high definition television (HDTV) p-Si technology is back of a-Si technology is back of a-Si technology. Because high temperature is required for its manufacturing, which is approx 600 degree centigrade. In HDTV to obtain the 1024 line, P-Si TFT technology proved well.

Signal crystal silicon (x-Si) technology which is in the primary stage. It has a large capacity to generate the high display resolution . Presently the research of x-Si technology is done by air force.

In TFT LCD monitor there are three different liquid crystal technology is used, it is known by TN+Film, IPS and MVA/PVA. This technology is described below:-

TN+Film(Twisted Nematic+Film):-

In TN+Film panel there is right angle of liquid crystal filter. In TN+Film panel there is another layer of “Film”, by which the view angle is increased.

TN+Film technology is easy to used. TN technology is used before many years. It uses can be viewed in the TFT panels which is used in different years before. To increase the viewing capacity of this panel, designer adds a film layer to it, by which the viewing angle is increased up to 150 degree from 90 degree. Now the working system is introduced to known, how zero voltage given on the sub pixel in thin film transistor then the liquid crystal rotates horizontally by an angle of 90 degree angle on the plate and light is passed away. If red, green and blue sub pixel is shining then that screen is observed as a white dot.

When the voltage is given to the film transistor in the form of electric field then these are makes a circular design of crystal. In this position of matter try to align itself in the direction of electric direction. In this posiyion the polarized light does not pass through the sub pixels and black will be obtained as white dot on screen.

IPS (IN-PLANE Switching):-

First generation of TFT LCD technology there is a decrement in viewing angle of TN+ Film after which the IPS technology is introduced. The viewing angle of this technology is 170 degree and the digital time is 50 to 60 ms.

If there is no voltage is on IPS system then liquid crystal does not rotate. Secondary filter is always parallel with the first filter. Therefore the light is always passes through this. Screen automatically seems black. This is a second field, in which these display is better display then its own TN rivals. If the transistor is burn then dead pixel becomes not sharp, becomes white not black. When not black. When the sub pixel exposed the voltage then two electrode makes electric field and rotate the crystal in parallel position to their right position then they a line with the polarizing filter and light passes through it.

MVA/PVA (Multi-Domain Vertical Alignment/Patterned Vertical Alignment):-

Some manufactures used MVA technology. In this technology the viewing angle of horizontal and vertical is 160 degree. The response time of this technology is half of IPS technology.

In this system, some crystal, which is not in the position of current, they were not vertical a line with the other filter. It means that light does not pass through it. As the voltage is generated crystal rotates by 90⁰and light passes through it, by which the white dot is display on the screen. The +ve consequence of this system is its speed. The response time of this system is less then 25ms.

LCD PANEL MANUFACTURING PROCESS:-

Front glass plate and rear glass plate and rear glass plate is used to make different lines. Mostly, maximum (4-6) display is obtained on plate. Rear glass plate is used for making the TFT in the position of active matrix LCDs. Transistor is created on the upper layer of ITO(Indian Tin Oxide) through PECVD(Plasma Enhanced Chemical Vapor Deposition). After this high coat, polyamide and spacer are used.

Like front glass plate, rear glass plate ITO, hard coat and celling, color filter have also the surface.

Two glass plates are mutually aliened and connected by using the UV high polymer soft in an assembled machine then raw panels are pressed each other and it is warmed by taking care of seal and a constant panel structure is created. After this to measure the final display the bigger display are tighten broken. Edge is grounded.

The construction of TFT is depend on many vacuum reactions, in which the for collection of PEVDCA-SI and gate de-electric insulation layer and by scanning the mental line for the ITO layer, TFT is created.

For the construction of TFT, the first pole is to give pertaining to each and every layer. Poly-silicon deposition process is used in case of a-Si position for the better quality of display p-Si deposition is done in the Take furnace of low pressure. This furnace is similar to the furnaces used for the other parts in a semi conductor industry. To make many layer in the TFT, lithographic equipment like resistance seppers and dry and wet is used. Through the high etching a better line width can be obtained but wet etching is a fast and less costly of mental in cover plate color filter this process is most costly for the manufacturing of TFT. There are so many process to prepare to front glass from color to filter. Dry and dust filter powder is spread on the glass, which is a simplest and less costly technology but in this process the maximum amont of filter material is unused. In the third process the layer of color filter is used on front glass and a protection layer is used above it.

After this substrate is used on ITO. After all through flax printer technology, SIOx and SOG is printed on the substrate and then it is placed in the furnace.

Under the cure process gas is poured on it. This process of pouring the gas is done with the help clean ovens or Hot plates.

Polyamide layer rubbing is necessary for the proper LC Alignment on the surface. This rubbing is aligned parallel with the polarized director direction. To keep the same distance on yhe two glass plate spacer spray is used on surface. With this spray, which is used In big display plastic. Three reactions can be used for this spray process. High spray, which is used in big display.

Semi spary is used for making the medium and small display. Wet spray is very less usable. But in this process same speaker is formed.

Screen printing technology is the best medium to seal the surface of both of this glass. Through this technology a large amount of output can be obtained of the best quality. Seal dispensing technology is mostly usable for the low production. The sealing material for the sealing purpose is firstly made in oven and then glass plates are used in assembly machine. After making of the seal it is sealed in Hot press oven.

After this the process of making the external connector is done. This process is done when the surface of glass plate is completed then silver paste is left on the printed line for making the connectors. Both the connected and aligned glass plate is keep on the sail assembly machine. That is already explained that the work os sealing is done after the sail assembly. After doing the fixing of glass plate in their right position of the sports through UV(Ultra Violet) light of both the glass plate in sail assembly then the process to seal the glass plate is completed. This process of sealing is done in true pressure with the thickness of seal. The thickness of seal and the thickness of LCD depends on the spacer. The process of filling of LCD is based on vacuum technology.

ASPECT RATIO AND DISPLAY AREA

There are two type of measurement for the size of display:-

(1) Aspect ration (2) Screen size

1.Aspect Ration: The meaning of Aspect Ration is that what is that what is the width and height of the display. The Aspect Ration of display of maximum computer is 4:3 it is called as format of picture. Aspect Ration is different for the resolution of some computer, which is understand by following table.

Resolution Aspect Ration Remark

320X240 4:3 Quarter VGA

640X400 16:10 EGA

640X480 4:3 VGA

800X480 15:9 Wide VGA

800X600 4:3 SVGA

1024X600 17:10 Wide SVGA

1024X768 4:3 XGA

1280X1024 5:4 SXGA

1400X1050 4:3 UXGA+

1600X1200 16:10 Wide UXGA

2048X1536 4:3 QXGA

2560X2048 4:3 QSXGA

2.Screen Size:- There is projection surface in all the types of display, which is normally called as screen. The measurement of size of screen is in the across inches, Screen size of a Laptop LCD panel is measure from one corner to another corner in the cross which is shown in a figure.

DOT PITCH OR PIXEL SIZE

Dot pitch indicates the sharpness of displayed image. It is measured in millimeter (MM) and less number indicates sharper the image. How the Dot Pitch is measured, it depends on the technology which is used.

Some manufactures used the horizontal dot pitch. To measure the horizontal dot pitch, two sub pixel of same color measures the horizontal distance of dot pitch. It is not vertically measured.

Example-If the dot pitch of TFT LCD is 0.28 MM then the horizontal dot pitch of that display can be 0.24MM. The dot pitch of a better quality of display is 0.26 MM and the horizontal dot pitch of that display should be 0.22MM.

Dot pitch can be converted directly in the resolution of screen. If we see the place of one square inch then hear we see that finite amont of dots, which depends on dot PITCH. Hear a table is given, in which no of dots is shown per square centimeter and per square inches in every common dot pitches.

Approx. Number of Approx. Number of

Dot Pitch Pixels/cm² Pixels/in²

.25MM 1,600 10,000

.26MM 1,444 9,025

.27MM 1,369 8,556

.28MM 1,225 7,656

RESOLUTION OF LIQUID CRYSWTAL DISPLAY(LCD):-

The number of one Dots (which is also called as pixels) on one display is called as “Resolution”. The number of pixels on the horizontal rows of the resolution and number of pixel on the vertical columns are shown as divination. For example-800 x 600. This resolution, is depends on the many other factors besides the screen size.

Some normal display standards and resolution are shown in the table given below-

VGA= Video Graphics Array 640 x RGB x 480 Dot

SVGA = Super Video Graphics Array 800 x RGB x 600 Dot

XGA= Extended Graphics Array 1,024 x RGB x 768 Dot

SXGA= Super Extended Graphics Array 1,280 x RGB x1,024 Dot

XSGA+= Super Extended Graphics Array 1,400 x RGB x 1,050 Dot

UXGA= Ultra Extended Graphics Array 1,600 x RGB x1,200 Dot

GUIDNCE OF HANDLING LCD PANEL

1. The screen of LCD Panel is made of soft polarizer. Dot not scratch or pressure on it.

2. Use rubber glove to touch the LCD screen. For cleaning it use soft cloth, anti static material or N-Hexane cleaner. Never use water.

3. Never use the LCD on high temperature and high Humidity and neither in the low temperature and low Humidity.

4. Corrosive gas may harm the polarizer circuit of TFT.

5. The CMOS electro-static are used as sensitive components in LCD module. Therefore, before opening or catch the LCD module earthed the body, do not touch the pin of signal interface connector of LCD module.

6. Do not keep the TFT LCD module in front of Sun Light.

7. Do not connector or disconnected the signal interface connector of TFT LCD module at the time of power ON.

8. The circuit of TFT LCD module works on the high frequency. Therefore, do not remove the grounding and shielding method given by the company.

9. Do not increase the length of back light connector cable connected in TFT LCD module, since the luminance of CCFL becomes less due to lengthy cable back light and in between the inverter. Because CCFL needs more startup voltage.

10. There is a glass in TFT LCD module. Therefore may break or crack on high surface after falling or crashing.

SW3	Power Switch	SW1	Lid Switch
JP1	Bluetooth Connector	JP5	Touchpad Connector
SW2	E-mail Switch	JP4	Keyboard Connector
SW4	Internet Browser Switch	JP42	Speaker Connector
SW5	Emanager Switch	JP7	PCMCIA Slot
SW6	User Programmable Switch	JP10	Microphone Connector
U8	LAN Controller Chip	U10	LAN Memory
U12	1.8V Supply Controller Mosfet	U13	South Bridge (ICH 6)
U15	CPU FAN Supply controller Section	U16	Left USB Connector Supply Controller
U17	+1.5VAWL to +1.5VS Supply Controller Mosfet	U20	Embended Controller or System Controller
U21	System Controller (EC) Memory	PU1	DC IN and dectector Section
PU3	Battery Charging Chip	PU4	Battery over voltage protection signal circuit
PU5	System power supply chip (+5VALWP, +3VALWP)	PU6	CPU Thermal Protection Circuit
PU7	CPU Power Supply Chip	PU8	+1.05VP Regulator IC
PU9	+1.5 VALWP and +1.8VP Supply PWM Controller IC	PU12	+0.9VP Supply Regulator IC

PQ6	Discharging Mosfet	PQ7	Battery Charging Mosfet
PQ10	+3VALWP Supply Regulator Mosfet	PQ11	+5VALWP Supply Regulator Mosfet
PQ14 PQ16 PQ19 PQ22	CPU Core Supply Mosfet	PQ25 PQ31	+1.5VALWP Supply Regulator Mosfet
PQ26 PQ27	1.8VP Supply Regulator Mosfet	PQ30	+0.9VP Supply Regulator Section Mosfet
PQ32	+1.05VP Supply Regulator Mosfet	T1	LAN MAGNETICS Solution Transformer
Y2	RTC Crystal Ocsilator

JP21	Fan Connector	JP24	USB Port
PJP11	Battery Connector	JP25	USB Port
JP20	CPU Socket	JP30	IEEE 1394 Port
JP16	LVDS Connector	JP36	Card Reader Connector
JP22	VGA Board Connector	IR	Infrared Receiver
PCN1	AC-IN	JP40	Headphone out/line-Out jack (support SPDIF)
JP13	USB Port	JP41	Mic-in Jack

JP12	Acer ez Dock (for TravelMate 3220 only)	JP28	HDD Connector
JP14	Modem Board Connector	JP35	Wireless LAN Card Connector
JP3	External Display Port	U42	BIOS
JP17	S-Video Port	JP26	DDR2 Socket
JP19	RJ11/RJ45	JP31	DDR2 Socket
JP23	Modem Cable Connector	JP39	ODD Connector
U29	Temperature Sensing	U31	North Bridge (GMCH
U33	Clock Generator IC	U34	Beep Sound Controller
U36	PCMCIA Power Controller	U39	PCMCIA Controller Chip
U40	Audio Codec Chip	U41	Audio Amplifier IC
U42	BIOS	U43	+3VALW to +3V Supply Controller Mosfet
U44	Audio Codec Chip Supply Regulator IC	U45	+5VALW to +5VS Supply Controller Mosfet
PL2 PL3	Battery Charging Section Coil	PL5	+3VALWP Supply Regulator Section Coil
PL6	+5VALWP Supply Regulator Section Coil	PL9 PL10	CPU Power Supply Section Coil
PL14	+1.5VALWP Supply Regulator Section Coil	PL15	+1.8VP Supply Regulator Section Coil
PL17	+1.05 VP Supply Regulator Section Coil	PL1	Adapter Supply Input Section Coil
PD26	Adapter Supply Input Section Diode	PQ4 PQ5	Adapter Supply Input Mosfet.
PU11	+2.5VP Supply Regulator IC	Y3	Clock Generator Section Crystal Ocsilator.
JP20	CPU Socket PGA479	X1

Laptop Troubleshooting (8050)

Trouble Shooting

1. No Power

2. Battery Can not Br Charged

3. No Display

4. External Monitor No Display

5. Memory Test Error

6. Keyboard/Touch pad Test Error

7. US

Mother Board And Laptop Repairing Full Course

MOTHER BOARD

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