37110553 LG 40 to 60 Inch Repair Guide Presentation

PDP One Point Repair Guide 1.. G 1 General en e r al 2. 40 ~ 5 50 0 In Inch ch P Practice ractice 3. 60 3. 60 IInch nch P Practice ractice

Symptom

Cause

Countermeasure

(Bad X-Board PCB)

Change X board

PCB Pattern Short

Red Bar at left lower

CHECK Point

1. Check after X-Board change 2. Do shortage check neighboring pins of FPC* connector 3. Check soldering condition of defect pin 4. Scan the pattern connected to defect pin with Microscpoe

2/88

*FPC : Flat Pin Connector

LG Electronics / DND / QA Gr.

Symptom

Cause

PCB

G

Countermeasure

R

Red

& Green pin of left lower 4th FPC short Change X-Board Defect Point : Short on the PCB just above

connector

1. Cause : Short by solder bridge - Can not observe with naked eye - When connector open, pattern is OK

Check Point

1. Check the contact status with connector(foreign material, soldering condition) 2. Replace X Board and check again.(If OK, X-Board is defected) 3. By tracing defected line, check thecontact condition of FPCand other connectors, IC output stage and PCB pattern. 4. If no problem, check the connector lead board.

3/88


Symptom

Cause

Pattern Short by connector miss insert

Countermeasure

Re-insert the Connector

Bottom Right 6th FPC R/B Short

Check Point

1. Check the contact status with connector(foreign material, soldering condition) 2. Replace X Board and check again.(If OK, X-Board is defected) 3. By tracing defected line, check the contact condition of FPC and other connectors, IC output stage and PCB pattern. 4. If no problem, check the connector lead board.

4/88


Symptom

Countermeasure

Cause

SHORT Foreign Material(Iron powder) in the Connector

X-Board Tape Rework

Gap

Insulation tape

ADD

Electrode short at R,G,B Raster or White Screen(Different color display)

 Apply silicon on the Connector lead

Pay attention to a capillary symptom 

Check Point

1. Trace defected line 2. Check the condition of FPC and connector on the X-Board, IC Output stage and Electrode line.

5/88


Symptom

Countermeasure

Cause

Keep horizontal, or can be defected

FPC connector Rework

OPEN

Interfere with mechanical structure when Module assembling

Cold soldering at Connector

1. Outbreak during heat run 2. ADD Electrode open at one colorRaster or White screen(No discharge)

 Use Connector fixing iron plate 

Keep the contact point horizontal when interfere with mechanical parts

Check Point

1. Trace defected line and check the condition of FPC and connector on X-Board, IC Output stage and Electrode line.

6/88


Symptom

Countermeasure

Cause

Replace the Panel

ADD Pattern

Connected minutely and open slowly as time passes

ADD open

Check Point

1. Replace X Board and check again(Still problem, change the Panel) 2. Check the connection status of Panel side. 3. Check the connection condition of connector of Panel side and the FPC at upper ACF.  If it is OK, check Panel pad

7/88


Symptom & Cause

Countermeasure

~ ADD Electrode open

Panel Electrode

at Green Raster

Replace the Panel

Open Electrode(16) 1. ADD pattern of PAD siden open 2. Width : 10 um

~

Resistance A

16pin

1.2

1,3,15,17,19pin

1.0 ~1.2

Resistance

6.0 2.2~2.4

B

Resistance

ACF

B

FPC Electrode Resistance A

Check Point

* The difference of ADD open and Short ? 1. Check the connection condition -Press the connector andreconnect ADD open : Black vertical 2. Check the soldering condition of Connector lead bar at Raster 3. Replace X Board and check again; Panel connector side or Circuit connector side ADD short : Different color  Board defect, in case of one line, check the output stage of Drive IC(Cold soldering/Pattern) vertical bar at If problems in input stage, several lines display Raster

8/88


Symptom

Countermeasure

Cause Control board

Con 1

Con 2

Change Control Board

X-board

< Raster >

< White > Solder bridge

ADD short at raster screen and ADD open at white screen appear at some area after 20 minute HeatRun.

Check Point

1. 2. 3. 4. 5.

Check the 5V(Logic voltage) input to DC-DC  If it is lower than 5V, it makes similar problem Check X Board(Open or Short circuit) Check the connection condition(conncetion status, foreign material at connector, etc) Check the drive IC at X Board(If defected, change the Board) Confirm the connection of the connector

9/88


Symptom

Countermeasure

Cause

Change X-BOARD X-DRV IC CLK LE

PCB pattern short

Short

R264 R258 U1

SN74ACT541

Check Point

Driver clock line at X Driver Board is designed to operate in A and B group  Short circuit at clock line of Drive IC  If problem at input stage, several lines are defected at one point  Replace the X Board of defected point

10/88


S ym p t o m

Countermeasure

Cause

connector 1

Chip Resistors

X driver chip (SN755851PJ) 4X16 = 64 data

Electrode Pattern

M o d u l e

Change X Board

64 16 clock line1 line2

 PCB pattern is connected minutely

 Foreign material when photo resisting

line3 line4

Check Point

1. Check the connection condition of the Connector. 2. Check the cold soldering.

11/88


Symptom

Countermeasure

Cause

Resistance

between 186 pin ofU3 and 7 pin of U300 is 62  Normal condition : 2 Change Control Board

Because of foreign material in Via hole at U300 side Via hole U3 ALTERA

Vertical bar in every 20mm

Chip

186pin PIN

U300 DRAM

7pin PIN

Control board

Check Point

1. Measure the resistance of Via holes betweenU3 and U300 at Control Board and compare with that of normal.(Normal : 2~3 ) 2. Resistance increases as temperature rises.

12/88


Symptom

Cause

Countermeasure

- Open circuit between pin 7 of U200 and pin 7 of U7 Replace Control Board - Resistance between two pins varies from 19 ohm ~ 45Kohm

Check Point

1. Observe the symptom during Heat-Run at 45 degree. 2. Check the resistance of VIA holes of suspect ICs

13/88


Symptom - When Power On, Fan operates but No DOS displays - LED(D3) of Control Board doesn¶t operate D1

D3

D4

Countermeasure

Cause

PROM(U40)

1. Because Control data on PROM(U40) doesn¶t download to FPGA, it can¶t generate control signal to X,Y and Z Board. 2. Defected ALTERA.

Replace Control Board Replace PROM

FPGA * For normal operation, P ROM program should be downloaded to FPGA, and each PROM has correspondent FPGA. See left picture.

CONTROL BOARD

Check Point

1. Check D1, D3 & D4 on Control Board - D1 : ON with 5V - D3 : ON when P ROM finishes program download fromALTERA chip - D4 : ON when signal is applied

14/88


Symptom

Cause

Countermeasure

Control Board

Replace Controller board

Touch point(M arked)

No signal or at PC mode, dark red raster displays. This is darker than normalRed signal.

 Neighboring Pins of U1(FPGA)

touch

Check Point

- TV VSC board - Board connector(50 pin) contact point - Control board of Module

15/88


Symptoms

Countermeasure

Cause 1. CN1 on Vs Board cold soldering 2. Spark marks between CN1 and Vs Board -> It m akes them open

Replace DC-DC 2 board Soldering Direction Soldering point

CN1 Vs board

1. No Raster(ST-BY LED On) 2. Spark noise(Tik-Tik) 3. No Vs, Vsetup & Vsc

Solder land

Solder Soldering Direction

Check Point

1. Check Vs, Va with multimeter(No Vs output) 2. Separate SMPS Board and VSC Board and check all voltage output stage 3. Check FET, TR, Diode and Resistor(especially CementResistor) 4. Observe PCB Pattern and soldering condition with naked eyes

16/88


40 ~ 42 Inch 42´ PDP Flicker and

42 Inch

No Raster Troubleshooting Guide cause : bad connection between Y-Board # 1, 2 drive board Connector pin

P6 Rework should be done P4 Y-Driver Board

Y-Board

17/88


 





P4

P6

 





amplified

amplified  : outside Leg  : inside Leg

P 6, P 4 both are the first pin, when wiring, it should be done as picture shown. (bend the wire to Y-Driver B/D not to Y-B/D . If not there can be noise)









Don¶t be confused with Pin number Improved since Dec,2001.

18/88




 





 



Be sure not to misconnect the line. See the picture precisely and then connect jump wire at the exact point

19/88


Intermittent no-image/image error while watching X CANVAS

X CANVAS

The screen is intermittently disappeared . LED is green

screen is distorted weiderly (happened 2 a day)

X CANVAS cause : bad connection between Y-Board and #1, 2 pin of Y-Drive Board Connector

troubleshooting : connect bad linking between Y-Board & Y-Drive with jump wire (all 4 parts)

,2001. 1) see working instruction(revised since Dec

normal 20/88


No Power X CANVAS

X CANVAS

No Power ( in ST-BY mode , but no LED)

normal

Check the power supply & main power S/W on Check EMI board fuse (check the rated capacity )

Be sure to use rated fuse. Fuse 15 A

21/88


No Raster X CANVAS

X CANVAS

when Power¶s on, after 2 ~ 3 sec, it¶s off ( LED changing green into red )

normal

CHECK : remove STB and operate monitor individually. (check STB defect or Monitor defect ) When using ANALOG STB, check STB only MN-42PZ10 only STB : RN-BA11 Remove each Board¶s power supply connector and check the power is off. When the power is not off ,replace the related board.

22/88


No Picture X CANVAS

X CANVAS

no picture (LED¶s green)

normal

Core checkpoint : remove STB and operate monitor individually. (check whether STB¶s a defect or monitor ¶s one) With monitor defect, check VSC and then Controller Board. Troubleshooting : replace VSC Board

23/88


Address Bar ( Horizontal Bar ) X CANVAS

X CANVAS

no image (LED¶s green)

normal

Cause : Y-Drive ( Bottom ) defect Troubleshooting : Y-Drive (lower part) replacement This problem is shown in the bottom of screen , So it is caused by Y-Drive

Y-Drive Board ( Bottom ) 24/88


Address Bar ( Horizontal Bar ) X CANVAS

X CANVAS


normal

Y-Drive Board ( Top ) Cause : Y-Drive Board (upper part) defect Troubleshooting : Y-Drive Board replacement

25/88


No Picture X CANVAS

X CANVAS


normal PD501 Connector

cause : PD-501 Connector contact point defect troubleshooting : PD-501 Connector replacement (with PD-501 Connector contact point defect, Various defect symptoms can be seen)

26/88


High frequency noise (³Bee´ sound) X CANVAS

X CANVAS

normal

normal picture with high frequency noise (³bee´) SMPS is supposed to operate with high frequency so small noise is not considered as a defect. Power (SMPS) Board 1. C8178 0.22/50V add 2. Open C8139 right lead, and then connect it to R8164 right lead.

Improved since Nov,2001

C8178 0.22uF electrolytic capacitor insertion

Open C8139 right lead and then wire R8164 right lead

#. Slight noise is not a defect and write down explanation 27/88


No picture in right- 2/ 5 area X CANVAS

X CANVAS

normal

No picture in the right- 2/ 5 area

X-Board ( Left ) power supply check X-Board ( Left )Connector check X-Board ( Left ) replacement

28/88


Address Bar (Vertical ) X CANVAS

X CANVAS

normal

stripe in right-2/5 area X-Board ( Left ) power supply check X-Board ( Left ) Connector check X-Board ( Left ) replacement

29/88


No picture in left 3/5 of the screen X CANVAS

X CANVAS

normal

left 3/5 of screen with vertical stripes

X-Board ( Right ) power supply check X-Board ( Right )Connector check X-Board ( Right ) replacement

30/88


Address Bar (Vertical ) X CANVAS

X CANVAS

normal

left 3/5 of screen with vertical stripes.

X-Board ( Right ) power supply check X-Board ( Right )Connector check X-Board ( Right ) replacement

31/88


No Red X CANVAS

X CANVAS

no Red ( B or G )

normal

Test Monitor individually. If detect a problem with monitor, check VSC Board. If it has a problem with STB connecting, focus on 25 Pin. Be sure not to connect 5 Pin (AP-EA10) by force 25 Pin Cable P/No : GVZ AP-EA 10

Be sure not to bend it by force or internal Insulated conductor can be down.

32/88


1) X - Board COF Connector separation Lift up the right and left of X-BOARD CONNECTOR.

42 Inch Lift up X-BOARD CONNECTOR and separate COP CONNECTOR by pulling up.

When you handle COF CONNECTOR, don¶t pressure. First release LOCK and separate. If COF CONNECTOR is damaged, you should replace MODULE ASS¶Y. So, be aware of this!!

COF Connector

Warning When you exchange X-Board, first you should separate COF Connector. Be careful to handle it. COF Connector is attached to Module. When COF Connector is broken, Module ASS¶Y must be replaced a new one.

33/88


2) X - Board Con nector separation

Liftupeachedgeofleft/right.

Liftedcondition Be careful to handle LOCK or it can be broken. ARD. When LOCK is broken, replace a new X-BO

Warning

It¶s easy to separate it by releasing Connector Lock . Do not pressure or it can be hurt. When LOCK is hurt, replace a new X-BOARD

34/88


3) Y - Board COF Connector separation

Pull the white LOCK as shown in arrow

Pull the white LOCK as shown in arrow.

Separate COF CONNECTOR by pulling in the left.

Warning

Be careful to handle LOCK and COF Connector. When LOCK part is damaged, you should replace a new Y-Board. In case of COF Connector, ModuleAssembly.

35/88


4)

Z - Board COF Connector separation

Separate the fixed Screw of Z-Board. Pull out Lock as shown in arrow.

Condition in Lock part is pulled

COF Connector

Warning

Be careful not to tear COF Connector. If COF Connector is torn, replace a new ModuleAssembly

36/88

Pull COF Connector as shown in arrow. It¶s easy to separate COF on condition that Z-Board Screw is separated. In case Z-Board is assembled, it¶s really hard to separate.


5) Connector separation Guide Push LOCK and pull out

PUSH

PUSH

PUSH

PUSH

PUSH

37/88

PULL


6) Control Board & VSC Board Connector

38/88


7)

Gas injection (Sealing up) condition

Be sealed up after gas injection

Be sealed up after gas injection

Warning

Be careful to handle the sealed-up part after gas injection. If it is broken, the gas escapes. So, replace the Module.

39/88


8) Power off in 2 ~ 3 minutes(Protection) Power is On and off 2~ 3 minutes. (Protection) P30 01 1C Connector onnector OOpen pen CCheck. heck.

OK

XX- B - Board oard ToTp op RiRigh ght C t hChang ange. e. OK

P30 02 2C Connector onnector OOpen pen CCheck heck

XX- B - Board oard ToTpop LeLe ft C ft hChang ange. e.

OK

P303 Connector Open Check


X - Board Bottom Right Change.

OK


X - Board Bottom Left Change. OK

P3, P2 Connector Open Check

Z - Board Change. OK

P005, P003 Connector Open Check PROTECT operation;


When the load voltage is short. When each voltage doesn¶t work (in general)

Y- Board Change.

OK

VSC- Board Change.

OK

VSC - Board Change. Sound Output IC Short Check

Power Board Change

40/88


9)

Power off in 2 ~ 3 minutes(Protection)

L813 Cold Solder

Symptom : As soon as the power on, it¶s off in 2 - 3minutes. (PROTECT operation) Cause : No VS voltage L813 Coil cold soldering.

Check

Open the Connector connecting to each Board to check the power is off. if each Board is same, check the Power Board and voltage.

41/88


10) ADD BAR inspection and repair

Press the ADJ KEY and check the position of addbar by changing WHITE or RED or BLUE or GREEN

HEATRUN : WHITE

T o pR ig h t

Bottom Right

To pL ef t

Bottom Left

MP-40PA10 uses 4 board such as left,right, top and bottom. Divide the screen in 4 and once you seeADD BAR check COF CONNECTOR between MODULE and X-BOARD. If there is no defect in COF CONNECTOR replace X-BOARD. But the problem still remains and check the connector between X-BO ARD and CONTROL BOARD. And if you can¶t find defect, check CONTROL.

42/88


11) One Point Service Guide

Symptom : B color 1 Address line Open Cause : Dented COF

COF is dented

43/88


Symptom : Inferior R Address color Cause : Inferior DATA output by cold soldering 16 pin of IC1 4 in X-L-TOP ( Normal waveform after tearing off IC Pin) Countermeasure : Replace X-L-TOP board.

IC14

Cold Soldering

Abnormal

waveform by cold soldering

Normal waveform after tearing off IC pin

44/88


Symptom

Causes

If 15V line voltage reduces below 1 4V, Mis-discharge occurs and power off because of protection circuit.

Countermeasure

Replace PSU (Power Supply Unit) and defective X-Board.

Defective X-Board

The blue spreads on the screen (Mis-discharge) and power off in 2 ~ 3 seconds. If you turn on again, it w ill be same problem.

Check If when Power on, screen shows like above and turn off in 2 seconds, check if turning off or not by disconnecting all X & Y boards.

45/88


Symptom

Cause

No 5V supply to Top right X-Board.

Countermeasure

Connect 5V line

The top left part of screen is broken (Top Right X-BOARD)

Check Check Top right X-BO ARD 5V.(If 0V, it happens) Check 5V line from SMPS to X-BO ARD.

46/88


Cause

Symptom

No Va(70V) supply to Top right X-Board.

Countermeasure

Connect 70V line

Pinkish screen in the top left. (Top right X-BOARD)

Check Check Top right X-BO ARD Va(70V).(If 0V, it happens) Check 70V(Va) line from SMPS to X-BO ARD.

47/88


Symptom

Cause

Countermeasure

No 12V supply to Top right X-Board.

Connect 12V line

No Va(70V) supply to Top right X-Board.

Connect 70V line

The 3/5 top left in t he screen is blank (Top Right X-BOARD) Check Check Top right X-BO ARD 12V.( If 0V, it happens ) Check Top right X-BO ARD Va(70V).(If 0V, it happens) Check 12V & 70V(Va) line from SMPS to X-BOARD.

48/88


Cause

Symptom

Countermeasure

No 12V supply to Top left X-Board.

Connect 12V line

No Va(70V) supply to Top left X-Board.

Connect 70V line

The 3/5 top right of t he screen is blank. (Top left X-BOARD)

Check Check Top left X-BOARD 12V.( If 0V, it happens ) Check Top left X-BOARD Va(70V).(If 0V, it happens) Check 12V & Va(70V) line from SMPS to X-BO ARD.

49/88


Cause

Countermeasure

P1 COF connector on Top left X-Board is open.

Reassemble it

Symptom

Pinkish screen in the 1/5 top right (Top left X-BOARD)

Check Check the contact point and Locking of P1 on Top left X-BOARD.

50/88


Symptom

Cause

No 5V supply to bottom right X-Board.

Countermeasure

Connect 5V line

The 3/5 bottom left of screen is br oken. (BOTTOM RIGHT X-BOARD)

Check Check Bottom right X-BOARD 5V.( If 0V, it happens ) Check 5V line from SMPS to X-BO ARD.

51/88


Cause

Symptom

No 12V supply to bottom right X-Board.

Countermeasure

Connect 12V line

No Va(70V) supply to bottom right X-Board.

The 3/5 bottom left of the screen i s Blank. (Bottom Right X-BOARD)

Check Check Bottom right X-BOARD 12V.( If 0V, it happens ) Check 12V line from SMPS to X-BO ARD.

52/88


Symptom

Cause

No 5V supply to bottom left X-Board.

Countermeasure

Connect 5V line

The 2/5 right of the screen is broken. (Bottom left X-BOARD)

Check Check Bottom left X-BOARD 5V.( If 0V, it happens ) Check 5V line from SMPS to X-BO ARD.

53/88


Cause

Symptom

No 12V supply to bottom left X-Board.

Countermeasure

Connect 12V line

The 2/5 right part of the screen is blank. (Bottom left X-BOARD )

Check Check Bottom left X-BOARD 12V.( If 0V, it happens ) Check 12V line from SMPS to X-BO ARD.

54/88


Cause

Countermeasure

The connecting of X-Board bottom left connector is bad.

Reassemble it.

Symptom

ADDRESS bar appears in the right bottom of the screen. (X-BOARD BOTTOM LEFT)

Check Check connecting of the connector of bottom left X-BO ARD. Reassemble it. X-BOARD BOTTOM LEFT CONNECTOR OPEN.

55/88


Examples

56/88


Symptom

Cause

Connector(P13) is OPEN or Connecting condition is bad

Countermeasure

Reassemble P13.

Screen is divided in top and bottom, and vertical bar appears.

Check

P13 CONNECTOR contact point inferior CHECK. P13 CONNECTOR SIGNAL CHEK.

P13 CONNECTOR

57/88


Symptom

Cause

Countermeasure

VSC Board C onnector i s Op en.

Reassemble VSC B oard Connector

Screen is broken and has the vertical/horizontal bar.

Check Check the connector connecting Reassemble the Connector

58/88


Symptom

Cause

Loose VSC Board Connector

Countermeasure

Reassemble VSC BO ARD Connector

The screen is bluish(Mosaic screen)

Check Check the connection condition of the Connector. Reassemble the Connector.

59/88


Symptom

Cause

Countermeasure

Bad IC203

Replace IC203(VPC3230D)

The mosaic appears in the screen when it connects Dto EO VIInput. (The sensibility of Y-signal is low.) When connected to Component Input, it is O.K.

Check

Check if X201 on VSC board oscillates. Check Video In/Out of IC203 on VSC board. IC201 (VPC3230D) Decoder IC

60/88


Examples

IC201(VPC3230D) Decoder is inferior

61/88


Cause Countermeasure

Symptom

Bad Connector connecting Control Board and VSC B/D.

Change the Connector

Abnormal

Normal

Noise with division of colors

Check Contact point and signal condition of Connector Control Board and VSC Board.

Bad Connector

62/88


Name

No signal Vertical Bar Symptom

Cause and Countermeasure 1.Cause : Bad IC2 (DA1)  IC2 DA1(Data Arrange) No.162 Pin output is changing

depending on the temperature. abnormal X-B¶d Buffer IC * Room temperature : 2.5V Output (Normal Pin = over 2.8V) * Heated : 1.5V Output(Normal Pin = 2.7V ) 

Bad IC2 ( DA1)

2. Countermeasure :Replace IC2 < Waveform of normal pin>

 heated

< Waveform of abnormal

pin >  heated

8cm

Realization

DA1

DA1

Buffer

Buffer

When ASIC Chip(IC2 DA1 LGD4001) on Control Board gets high temperature, you can observe it (In normal temperature it¶s O.K. ) Buffer(74ACT541) waveform abnormally narrows. In this case, it is impossible for Flip Flop( 74AC574) on X B/D to read data.

63/88


Name

Add

Open (Green 1 Line) Symptom

Cause and Countermeasure 1.cause: Add. COF Drive IC inferior

Add.

Normal Line Data waveform

COF Drive IC

Open Line Data output waveform

 the output of inferior line less than that of the normal Line Add.

COF Drive IC inferior

 COF inspection  : 24V Open check (normal 50V)

64/88


Name

Vertical bar when Power off/on(Mis-discharge) Symptom

Cause and Countermeasure 1.Cause : Control board malfunctions when Power off/on. 2.Countermeasure: Change some parts on Control board. 3.Changing parts :A32_CTRL_03 B/D (Marked on PCB) -.R14,17,18,21 : 330 ==> 4.7K (Chip Resistor) -.R15,16,19,20 : 22K ==> 4.7K (Chip Resistor) -.C504, 505 : 0.1uF / 50V add (Chip Capacitor) Control board

Realization

1.PDP Power on Mode external input (regardless of wire/wireless signal but it¶s easy to reenact in wireless signal) 2. Remove Power Cord (Power¶s off) 3.after about 20minutes, insert Power cord (automatically the Power¶s on and the vertical bar i s shown as above)

65/88


50 Inch

X CANVAS

X CANVAS

Bottom Center No Picture

Normal

MODEL : MN-50PZ40S Check Point : Cable & X-Board

Symptom : ADD Bar(No signal)

Action : Module Control Change

66/88


X CANVAS

X CANVAS

Bottom Center X-Board

Normal

MODEL : MN-50PZ40S Check Point : X-Board (Bottom) Symptom : ADD Bar Action : X Board Change

67/88


X CANVAS

X CANVAS

Horizontal Bar

Normal

Check Point : Y-Drive Board Symptom : Horizontal Bar Action : Y-Drive Board Change & Connector Clean

68/88


60 Inch

Power PCB Voltage Adjustment TP5 GND

VA Adjust

When replacing PDP module & power board, Be sure to adjust Power Ass¶y voltage.

TP6 VA

VR8401

VS Adjust VR8501 TP3 GND

TP4 VS

DMM +

PFC +

1. PFC adjustment

PFC -

-. Select 100% White Pattern signal and warm it up enough. -. Connect DMM with TP PFC+ and TP PFC ± (GND). -. adjust V R801 to 380V (within ±1V ).

380V ± 1V VR801

2. Va adjustment -. Connect DMM + terminal with P814 #1 Pin. -. Turn VR8401 (Va Adj) to adjust the voltage on DMM to Va voltage value marked on panel bottom- right label. (allowable error : ±0.5V )

PFC PACK

3. Vs adjustment -. Connect DMM¶s + terminal with P803 # 9 Pin. -. Turn VR 8501 (Vs Adj )to adjust the voltage on DMM to Vs voltage value marked on p anel bottom-right label.

69/88


Power Supply Section

Power & no Raster

AC input check (220V)

Connection Plug with set

When Main S/W ON, ST-BY LED ON check (RED)

AC Line Fuse check

When SUB S/W on, LED GREEN check

PFC Board R8301,R8302 R8303 OPEN check

R8301,R8302,R8303 replacement

R8538, R8539,R8540 OPEN check

FAN function check

5V MONI, 5V CTL output check

VS, VA PACK Function check

Controller Board VS ON check

Controller Board replacement

each Connector & connection check

70/88


Sound Section

Connector between SP & set check

Sound power (P806A,B) Cable connection check

IC601 (MSP3401) check

IC603 (LA4282) check

Sound terminal Voltage check (32V)

F8811 Fuse Open check

71/88

Input jack check (25Pin cable L,R input check)

Speaker connection line check


Video Signal Section Abnormal screen

PC signal input

IC501 ( JAGASM check )

IC203 ( CXA2101 ) check

IC901 (SII 150 ) check)

IC406 ( ADV 7123 ) check

P901 ( 21 Pin cable ) check

IC404 ( FLI2220 ) check

IC403 ( FLI2220 )check

IC201 (VPC3230 ) check

Input jack & Connector check 72/88


No power X CANVAS

X CANVAS

normal

No power ( LED is not on in ST-BY)

AC power voltage check

Main Power S/W check

F8301 Fuse (15A) check F8301 Fuse (15A) replacement F8302 Fuse check

73/88


On-and-off Disappearing or error while watching X CANVAS

X CANVAS

normal

Intermittent image disappearing. LED¶s green

Cause : Y-Board VR301 waveform adjustment defect Troubleshooting : Y-Board VR301 Adjust

See the next instruction(improved since Dec,2001)

74/88


Auto power off Automatic off as soon as power is on ( Protect ) X CANVAS

X CANVAS

normal

Automatic off after 2~3 seconds ( Protect )

Cause : X-Board internal IC Short

Troubleshooting: replace the defective X-Board & DC-DC Board

*. Remove X ± Board power supply connector to check whether power is off.

X - Board

75/88


Auto power off Automatic off as soon as power is on ( Protect ) X CANVAS

X CANVAS

Automatic off after 2

Cause : Y

±

±

normal

3 seconds ( Protect )

Board 220V Line Short

Troubleshooting : Y

±

Board replacement

*. Remove Y ± Board power supply connector to check Whether power is off.

Y - Board 76/88


Address Bar(Horizontal) X CANVAS

X CANVAS

One horizontal line in the top part

normal

Y-Board & Y-Drive Board Connector check

Y-Drive Board ( Top ) Drive IC check

Y-Drive Board replacement

77/88



X CANVAS

normal

Single horizontal bar in the bottom

X CANVAS Y-Board & Y-Drive Board Connector check

Y-Drive Board ( Bottom ) Drive IC check


78/88



X CANVAS

normal

Image is on and off. LED¶s green

Y-Board & Y-Drive Board Connector check

Y-Drive Board ( Top ) Drive IC check


79/88



X CANVAS

normal

Green dot line on the screen

VSC Board & Controller Board Connector check

Controller Board check

Controller Board replacement

80/88


Address Bar(Vertical) X CANVAS

X CANVAS

Address Bar. ( Red Pattern reception )

Address Bar. (Gray Pattern reception)

X CANVAS

X-Board COF Drive IC check

X-Board Connector check X-Board replacement

Module ( Panel )replacement

81/88


Address Bar(Vertical) X CANVAS

X CANVAS

Intermittent image disappearing. LED is green

image distorted (occurring twice a day)

X CANVAS

X-Board COF Drive IC check

X-Board Connector check X-Board replacement

Module ( Panel )replacement

normal 82/88


Address Bar(Vertical) Address Bar ( Vertical ) & partial no-picture X CANVAS

X CANVAS

Central top 4/10 of the screen with vertical bar

Central top 4/10 of screen with no-picture

X CANVAS

related X-Board power supply voltage check

related X-Board Connector check

related X-Board & Controller Board Connector check

related X-Board replacement

normal

Module (Panel ) check

83/88



X CANVAS

Bottom left 3/10 of the screen wit h vertical bar

Bottom left 3/10 of the screen with no-picture

Related X-Board power supply volt age check

X CANVAS

Related X-Board Connector check

Related X-Board & Controller Board Connector check

Related X-Board replacement


normal 84/88



X CANVAS

Bottom right 3/10 of the screen with no-picture

Bottom right 3/10 of the screen with vertical bar

X CANVAS

related X-Board power supply voltage check

Related X-Board Connector check



normal


85/88



X CANVAS

Central bottom 4/10 of the screen wit h vertical bar

Central bottom 4/10 of the screen with no-picture

X CANVAS

Related X-Board power supply voltage check Related X-Board Connector check



normal


86/88



X CANVAS

Top right 3/10 of the screen with vertical bar

Top right 3/10 of the screen with no-picture

X CANVAS




normal


87/88



X CANVAS

Top left 3/10 of the screen with no-picture

Top left 3/10 of the screen with vertical bar

X CANVAS





normal 88/88


37110553 LG 40 to 60 Inch Repair Guide Presentation

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