LG Plasma Schematic

PDP One Point Repair Guide

PDP One Point Repair Guide

1.

1.

2.

2.

3.

3.

General

General

40 ~ 50 Inch Practice

40 ~ 50 Inch Practice

60 Inch Practice

60 Inch Practice

1

Symptom Cause

(Bad X-Board PCB)

Countermeasure

Change X board

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

PCB Pattern Short

*FPC : Flat Pin Connector

LG Electronics / DND / QA Gr.

Symptom

Cause

Countermeasure

PCB

G

Red & Green pin of
left lower 4th FPC
short

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)

R

Change X-Board

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.

3/88

LG Electronics / DND / QA Gr.

Symptom Cause

Countermeasure

Pattern Short by connector miss insert

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.

Re-insert the Connector

4/88

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SHORT

Symptom Cause

Foreign Material(Iron powder)
in the Connector

Gap

Countermeasure

X-Board Tape Rework

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

LG Electronics / DND / QA Gr.

Symptom Cause

OPEN

1. Outbreak during heat run

2. ADD Electrode open at one color Raster
or White screen(No discharge)

Keep horizontal, or
can be defected

Interfere with mechanical
structure when Module
assembling

Cold soldering at
Connector

▶ Use Connector fixing iron plate
⇒ Keep the contact point horizontal
when interfere with mechanical parts

Countermeasure

FPC connector Rework

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

LG Electronics / DND / QA Gr.

Symptom Cause

Countermeasure

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

Replace the Panel

7/88

LG Electronics / DND / QA Gr.

CountermeasureSymptom & Cause

~

ADD Electrode open

at Green Raster

~

16pin

1,3,15,17,19pin

Resistance A Resistance B

1.2Ω 6.0Ω

1.0 ~1.2Ω 2.2~2.4Ω

Panel Electrode

ACF

Open Electrode(16)

1. ADD pattern of
PAD siden open

2. Width : 10 um

Resistance B

FPC

Electrode

Resistance A

Check Point

1. Check the connection condition - Press the connector and reconnect

2. Check the soldering condition of Connector lead

3. Replace X Board and check again; Panel connector side or Circuit connector side
→ Board defect, in case of one line, check the output stage of Drive IC(Cold soldering/Pattern)
If problems in input stage, several lines display

Replace the Panel

* The difference of ADD open
and Short ?
ADD open : Black vertical
bar at Raster
ADD short : Different color
vertical bar at
Raster

8/88

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Symptom Cause

Control board

Countermeasure

Con 2

X-board

Solder bridge

< Raster >

Con 1

< White >

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

Check Point

1. Check the 5V(Logic voltage) input to DC-DC → If it is lower than 5V, it makes similar problem

2. Check X Board(Open or Short circuit)

3. Check the connection condition(conncetion status, foreign material at connector, etc)

4. Check the drive IC at X Board(If defected, change the Board)

5. Confirm the connection of the connector

Change Control Board

9/88

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Symptom Cause

Countermeasure

Change X-BOARD

X-DRV IC

CLK LE

PCB pattern short

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

R264
R258

SN74ACT541

Short

U1

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Symptom Cause

<X-board>

Countermeasure

connector

▶ PCB pattern is connected minutely
→ Foreign material when photo resisting

Check Point

1. Check the connection condition of the Connector.

2. Check the cold soldering.

Electrode

Pattern

Chip

Resistors

4X16

= 64 data

1

(SN755851PJ)

64

line1
line2

line3
line4

X driver

chip

16 clock

M

o
d
u

l

e

Change

X Board

11/88

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Symptom Cause

Resistance between 186 pin of U3 and
7 pin of U300 is 62 Ω
Normal condition : 2Ω

Countermeasure

Because of foreign material in Via hole
at U300 side

Via hole

U300

DRAM

7pin PIN

Vertical bar in every 20mm

U3

ALTERA Chip

186pin PIN

Control board

Check Point

1. Measure the resistance of Via holes between U3 and U300 at Control Board and compare with
that of normal.(Normal : 2~3 Ω)

2. Resistance increases as temperature rises.

Change Control Board

12/88

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Symptom Cause

- Open circuit between pin 7 of U200 and pin 7
of U7

- Resistance between two pins varies from
19 ohm ~ 45Kohm

Countermeasure

Replace Control Board

Check Point

1. Observe the symptom during Heat-Run at 45 degree.

2. Check the resistance of VIA holes of suspect ICs

13/88

LG Electronics / DND / QA Gr.

Symptom Cause

- When Power On, Fan operates but No OSD
displays

- LED(D3) of Control Board doesn’t operate

D1 D3

D1 D3

FPGA

FPGA

D4

D4

CONTROL BOARD

PROM(U40)

PROM(U40)

Countermeasure

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

* For normal operation, PROM program should be
downloaded to FPGA, and each PROM has corr­ espondent FPGA. See left picture.

Check Point

1. Check D1, D3 & D4 on Control Board

- D1 : ON with 5V

- D3 : ON when PROM finishes program download from ALTERA chip

- D4 : ON when signal is applied

14/88

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Symptom Cause

Control Board

Touch point(Marked)

Countermeasure

Replace Controller board

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

Check Point

- TV VSC board

- Board connector(50 pin) contact point

- Control board of Module

▶ Neighboring Pins of U1(FPGA)
touch

15/88

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Symptoms Cause

1. CN1 on Vs Board cold soldering

2. Spark marks between CN1 and Vs Board

-> It makes them open

Countermeasure

Replace DC-DC 2 board

Soldering Direction

CN1

Vs board

Solder land

1. No Raster(ST-BY LED On)

2. Spark noise(Tik-Tik)

3. No Vs, Vsetup & Vsc

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 Cement Resistor)

4. Observe PCB Pattern and soldering condition with naked eyes

Soldering point

Solder

Soldering Direction

16/88

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40 ~ 42 Inch

42 Inch

42” PDP Flicker and

42” PDP Flicker and

No Raster Troubleshooting

No Raster Troubleshooting

P6

P4

Guide

Guide

cause : bad connection between
Y-Board
# 1, 2 drive board Connector pin

Rework should
be done

Y-Board

17

Y-Driver Board

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②

P 6

①

①

②

amplified

②

②

① : outside Leg
② : 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.

①

P 4

①

②

①

amplified

①

②

18

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②

①

①

②

②

①

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

19

①

②

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Intermittent no-image/image error while watching

CANVAS

X

The screen is intermittently disappeared . LED is green

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

CANVAS

X

screen is distorted weiderly (happened 2 a day)

CANVAS

X

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

see working instruction(revised since Dec,2001.

1)

20

normal

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No Power

CANVAS

X

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

Check the power supply & main power S/W on

CANVAS

X

normal

Check EMI board fuse (check the rated capacity )

Be sure to use rated fuse.

21

Fuse 15 A

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No Raster

CANVAS

X

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

CHECK : remove STB and operate monitor individually.
(check STB defect or Monitor defect )

CANVAS

X

normal

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

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CANVAS

X

CANVAS

X

No Picture

no picture (LED’s green)

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

normal

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Address Bar ( Horizontal Bar )

CANVAS

X

no image (LED’s green)

Cause : Y-Drive ( Bottom ) defect

CANVAS

X

normal

Troubleshooting : Y-Drive (lower part) replacement

This problem is shown in the bottom of screen,
So it is caused by Y-Drive

24

Y-Drive Board ( Bottom )

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Address Bar ( Horizontal Bar )

CANVAS

X

no image (LED’s green)

Cause : Y-Drive Board (upper part) defect

CANVAS

X

normal

Y-Drive Board ( Top )

Troubleshooting : Y-Drive Board replacement

25

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CANVAS

X

CANVAS

X

No Picture

no image (LED’s green)

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

normal

PD501 Connector

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High frequency noise (“Bee” sound)

CANVAS

X

normal picture with high frequency noise (“bee”)

SMPS is supposed to operate
with high frequency so
small noise is not considered
as a defect.

CANVAS

X

normal

Power (SMPS) Board

1. C8178 0.22㎌/50V add

2. Open C8139 right lead,
and then connect it to
R8164 right lead.

C8178 0.22uF
electrolytic

Improved since Nov,2001

capacitor insertion

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

27

Open C8139 right
lead and then
wire R8164 right
lead

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No picture in right- 2/5 area

CANVAS

X

No picture in the right- 2/5 area

X-Board ( Left ) power supply check

CANVAS

X

normal

X-Board ( Left )Connector check

X-Board ( Left ) replacement

28

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Address Bar (Vertical )

CANVAS

X

stripe in right-2/5 area

X-Board ( Left ) power supply check

X-Board ( Left ) Connector check

CANVAS

X

normal

X-Board ( Left ) replacement

29

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No picture in left 3/5 of the screen

CANVAS

X

left 3/5 of screen with vertical stripes

X-Board ( Right ) power supply check

CANVAS

X

normal

X-Board ( Right )Connector check

X-Board ( Right ) replacement

30

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Address Bar (Vertical )

CANVAS

X

left 3/5 of screen with vertical stripes.

X-Board ( Right ) power supply check

CANVAS

X

normal

X-Board ( Right )Connector check

X-Board ( Right ) replacement

31

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No Red

CANVAS

X

no Red ( B or G )

Test Monitor individually.
If detect a problem with monitor, check VSC Board.

CANVAS

X

normal

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-EA10

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

32

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1) X - Board COF Connector separation

42 Inch

Lift up the right and left of X-BOARD CONNECTOR.

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!!

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

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

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2) X - Board Connector separation

Lift up each edge of left/right. Lifted condition

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

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

LG Electronics / DND / QA Gr.

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, Module Assembly.

35

LG Electronics / DND / QA Gr.

4) Z - Board COF Connector separation

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

Warning

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

Condition in Lock part is pulled Pull COF Connector as shown in arrow.

36

COF Connector

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.

LG Electronics / DND / QA Gr.

5) Connector separation Guide

Push LOCK and pull out

PUSH

PUSH

PUSH

PUSH

PUSH

PULL

37

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6) Control Board & VSC Board Connector

38

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7) Gas injection (Sealing up) condition

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

Be sealed up after gas injection

LG Electronics / DND / QA Gr.

8) Power off in 2 ~ 3 minutes(Protection)

Power is On and off 2~3 minutes.

(Protection)

P301 Connector Open Check. X - Board Top Right Change.

P302 Connector Open Check X - Board Top Left Change.

P303 Connector Open Check

P304 Connector Open Check

P102 Connector Open Check

OK

OK

OK

X - Board Bottom Right Change.

OK

X - Board Bottom Left Change.

OK

Z - Board Change.

OK

P3, P2 Connector Open Check

P005, P003 Connector Open Check

OK

Y - Board Change.

VSC- Board Change.

PROTECT operation;

When the load voltage is short.

When each voltage doesn’t work (in general)

P006 Connector Open Check

Power Board Change

40

OK

VSC - Board Change.

Sound Output IC Short Check

LG Electronics / DND / QA Gr.

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

LG Electronics / DND / QA Gr.

10) ADD BAR inspection and repair

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

HEATRUN : WHITE

Top Right Top Left

Bottom Right

Bottom Left

MP-40PA10 uses 4 board such as left,right, top and bottom.
Divide the screen in 4 and once you see ADD 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-BOARD and
CONTROL BOARD. And if you can’t find defect, check CONTROL.

42

LG Electronics / DND / QA Gr.

11) One Point Service Guide

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

COF is dented

43

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IC14

Symptom : Inferior R Address color
Cause : Inferior DATA output by cold soldering 16 pin of IC14 in X-L-TOP

( Normal waveform after tearing off IC Pin)

Countermeasure : Replace X-L-TOP board.

Cold Soldering

Abnormal waveform by cold soldering

Normal waveform after tearing off IC pin

44

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Symptom Causes Countermeasure

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

Check

If 15V line voltage reduces
below 14V,
Mis-discharge occurs and
power off because of
protection circuit.

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

Defective X-Board

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

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Symptom

Cause

Countermeasure

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

Check

Check Top right X-BOARD 5V.(If 0V, it happens)

No 5V supply to Top right
X-Board.

Connect 5V line

Check 5V line from SMPS to X-BOARD.

46

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Symptom

Cause

Countermeasure

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

Check

Check Top right X-BOARD Va(70V).(If 0V, it happens)

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

Connect 70V line

Check 70V(Va) line from SMPS to X-BOARD.

47

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Symptom

Cause

Countermeasure

The 3/5 top left in the screen is blank
(Top Right X-BOARD)

Check

Check Top right X-BOARD 12V.( If 0V, it happens )

No 12V supply to Top right
X-Board.

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

Connect 12V line

Connect 70V line

Check Top right X-BOARD Va(70V).(If 0V, it happens)

Check 12V & 70V(Va) line from SMPS to X-BOARD.

48

LG Electronics / DND / QA Gr.

Symptom

Cause

Countermeasure

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

Check

Check Top left X-BOARD 12V.( If 0V, it happens )

No 12V supply to Top left
X-Board.

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

Connect 12V line

Connect 70V line

Check Top left X-BOARD Va(70V).(If 0V, it happens)

Check 12V & Va(70V) line from SMPS to X-BOARD.

49

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Symptom

Cause

Countermeasure

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

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.

Reassemble it

50

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Symptom

Cause

Countermeasure

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

Check

No 5V supply to bottom right
X-Board.

Connect 5V line

Check Bottom right X-BOARD 5V.( If 0V, it happens )

Check 5V line from SMPS to X-BOARD.

51

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Symptom

Cause

Countermeasure

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

Check

No 12V supply to bottom right
X-Board.

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

Connect 12V line

Check Bottom right X-BOARD 12V.( If 0V, it happens )

Check 12V line from SMPS to X-BOARD.

52

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Symptom

Cause

Countermeasure

Check

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

No 5V supply to bottom left
X-Board.

Connect 5V line

Check Bottom left X-BOARD 5V.( If 0V, it happens )

Check 5V line from SMPS to X-BOARD.

53

LG Electronics / DND / QA Gr.

Symptom

Cause

Countermeasure

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

Check

No 12V supply to bottom left
X-Board.

Connect 12V line

Check Bottom left X-BOARD 12V.( If 0V, it happens )

Check 12V line from SMPS to X-BOARD.

54

LG Electronics / DND / QA Gr.

Symptom

Cause

Countermeasure

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

Check

Check connecting of the connector of bottom left X-BOARD.

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

Reassemble it.

Reassemble it.

55

X-BOARD BOTTOM LEFT CONNECTOR
OPEN.

LG Electronics / DND / QA Gr.

Examples

56

LG Electronics / DND / QA Gr.

Symptom

Cause

Countermeasure

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

Check

P13 CONNECTOR contact point inferior CHECK.

Connector(P13) is OPEN or
Connecting condition is bad

Reassemble P13.

P13 CONNECTOR SIGNAL CHEK.

57

P13 CONNECTOR

LG Electronics / DND / QA Gr.

Symptom

Screen is broken and has the vertical/horizontal bar.

Cause

VSC Board Connector is Open. Reassemble VSC Board

Countermeasure

Connector

Check

Check the connector connecting

Reassemble the Connector

58

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Symptom

The screen is bluish(Mosaic screen)

Cause

Loose VSC Board Connector Reassemble VSC BOARD

Countermeasure

Connector

Check

Check the connection condition of the Connector.

Reassemble the Connector.

59

LG Electronics / DND / QA Gr.

Symptom

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

Cause

Countermeasure

Bad IC203 Replace IC203(VPC3230D)

Check

Check if X201 on VSC board oscillates.
Check Video In/Out of IC203 on VSC board.

60

IC201
(VPC3230D)
Decoder IC

LG Electronics / DND / QA Gr.

Examples

IC201(VPC3230D) Decoder is inferior

61

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Abnormal Normal

Noise with division of colors

Symptom

Cause

Countermeasure

Bad Connector connecting
Control Board and VSC B/D.

Change the Connector

Check

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

62

Bad Connector

LG Electronics / DND / QA Gr.

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

8cm

Realization

When ASIC Chip(IC2 DA1 LGD4001) on Control Board gets
high temperature, you can observe it
(In normal temperature it’s O.K. )

< Waveform of normal pin>

─ heated

Buffer(74ACT541) waveform abnormally narrows.
→In this case, it is impossible for Flip Flop(74AC574) on X
B/D to read data.

63

DA1

Buffer

< Waveform of abnormal pin

>

─ heated

DA1

Buffer

LG Electronics / DND / QA Gr.

Name Add Open (Green 1 Line)

Symptom Cause and Countermeasure

1.cause: Add. COF Drive IC inferior

Add. COF Drive IC

Normal Line Data waveform

▶ the output of inferior line less than that of the normal Line
Add. COF Drive IC inferior

▶ COF inspection검사기 : 24V Open check (normal 50V)

64

Open Line Data output waveform

LG Electronics / DND / QA Gr.

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 is shown as above)

65

LG Electronics / DND / QA Gr.

50 Inch

CANVAS

X

Bottom Center No Picture

MODEL : MN-50PZ40S

Check Point : Cable & X-Board

Symptom : ADD Bar(No signal)

Action : Module Control Change

66

CANVAS

X

Normal

LG Electronics / DND / QA Gr.

CANVAS

X

CANVAS

X

Bottom Center X-Board

MODEL : MN-50PZ40S

Check Point : X-Board (Bottom)

Symptom : ADD Bar

Action : X Board Change

67

Normal

LG Electronics / DND / QA Gr.

CANVAS

X

CANVAS

X

Horizontal Bar

Check Point : Y-Drive Board

Symptom : Horizontal Bar

Action : Y-Drive Board Change & Connector Clean

68

Normal

LG Electronics / DND / QA Gr.

60 Inch

<SMPS Board>

TP5 GND

Power PCB Voltage Adjustment

When replacing PDP module & power board,

Be sure to adjust Power Ass’y voltage.

PFC +

PFC -

VR801

380V ± 1V

PFC PACK

VA Adjust

VR8401

VS Adjust

VR8501

TP3

GND

TP6 VA

TP4

VS

DMM

+

1. PFC adjustment

-. Select 100% White Pattern signal and warm it up enough.

-. Connect DMM with TP PFC+ and TP PFC – (GND).

-. adjust VR801 to 380V (within ±1V ).

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 )

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 panel bottom-right label.

69

LG Electronics / DND / QA Gr.

Power & no Raster

Power Supply Section

AC input check (220V)

When Main S/W ON,

ST-BY LED ON check (RED)

When SUB S/W on,

LED GREEN check

R8538, R8539,R8540

OPEN check

VS, VA PACK

Function check

Connection Plug with set

AC Line Fuse check

PFC Board R8301,R8302

R8303 OPEN check

FAN function check

Controller Board

VS ON check

R8301,R8302,R8303 replacement

5V MONI, 5V CTL output check

Controller Board replacement

each Connector

& connection check

70

LG Electronics / DND / QA Gr.

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

Input jack check

(25Pin cable L,R input check)

Speaker connection

line check

71

LG Electronics / DND / QA Gr.

Abnormal screen

Video Signal Section

PC signal input

IC203 ( CXA2101 ) check

IC406 ( ADV 7123 ) check

IC404 ( FLI2220 ) check

IC403 ( FLI2220 )check

IC501 ( JAGASM check )

IC901 (SII 150 ) check)

P901 ( 21 Pin cable ) check

IC201 (VPC3230 ) check

Input jack

& Connector check

72

LG Electronics / DND / QA Gr.

No power

CANVAS

X

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

AC power voltage check

CANVAS

X

normal

Main Power S/W check

F8301 Fuse (15A) check

F8302 Fuse check

F8301 Fuse (15A) replacement

73

LG Electronics / DND / QA Gr.

Disappearing or error while watching

On-and-off

CANVAS

X

Intermittent image disappearing. LED’s green

Cause : Y-Board VR301 waveform adjustment defect

Troubleshooting : Y-Board VR301 Adjust

CANVAS

X

normal

See the next instruction(improved since Dec,2001)

74

LG Electronics / DND / QA Gr.

Automatic off as soon as power is on ( Protect )

Auto power off

CANVAS

X

Automatic off after 2~3 seconds ( Protect )

Cause : X-Board internal IC Short

CANVAS

X

normal

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

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

75

X - Board

LG Electronics / DND / QA Gr.

Automatic off as soon as power is on ( Protect )

Auto power off

CANVAS

X

Automatic off after 2 – 3 seconds ( Protect )

Cause : Y – Board 220V Line Short

CANVAS

X

normal

Troubleshooting : Y – Board replacement

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

76

Y - Board

LG Electronics / DND / QA Gr.

Address Bar(Horizontal)

CANVAS

X

One horizontal line in the top part

Y-Board & Y-Drive Board Connector
check

CANVAS

X

normal

Y-Drive Board ( Top ) Drive IC check

Y-Drive Board replacement

77

LG Electronics / DND / QA Gr.

Address Bar(Horizontal)

CANVAS

X

Single horizontal bar in the bottom

Y-Board & Y-Drive Board Connector
check

CANVAS

X

CANVAS

X

normal

Y-Drive Board ( Bottom ) Drive IC check

Y-Drive Board replacement

78

LG Electronics / DND / QA Gr.

Address Bar(Horizontal)

CANVAS

X

Image is on and off. LED’s green

Y-Board & Y-Drive Board Connector
check

CANVAS

X

normal

Y-Drive Board ( Top ) Drive IC check

Y-Drive Board replacement

79

LG Electronics / DND / QA Gr.

Address Bar(Horizontal)

CANVAS

X

Green dot line on the screen

CANVAS

X

normal

VSC Board & Controller Board Connector check

Controller Board check

Controller Board replacement

80

LG Electronics / DND / QA Gr.

Address Bar(Vertical)

CANVAS

X

Address Bar. (Gray Pattern reception)

X-Board COF Drive IC check

CANVAS

X

CANVAS

X

Address Bar. ( Red Pattern reception )

X-Board Connector check

Module ( Panel )replacement

X-Board replacement

81

LG Electronics / DND / QA Gr.

Address Bar(Vertical)

CANVAS

X

Intermittent image disappearing. LED is green

X-Board COF Drive IC check

CANVAS

X

image distorted (occurring twice a day)

CANVAS

X

X-Board Connector check

Module ( Panel )replacement

X-Board replacement

82

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Central top 4/10 of the screen with vertical bar

related X-Board power supply voltage check

related X-Board Connector check

CANVAS

X

Central top 4/10 of screen with no-picture

CANVAS

X

related X-Board & Controller Board Connector check

related X-Board replacement

Module (Panel ) check

83

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Bottom left 3/10 of the screen with vertical bar

Related X-Board power supply voltage check

Related X-Board Connector check

CANVAS

X

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

CANVAS

X

Related X-Board & Controller Board Connector check

Related X-Board replacement

Module (Panel ) check

84

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Bottom right 3/10 of the screen with vertical bar

related X-Board power supply voltage check

Related X-Board Connector check

CANVAS

X

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

CANVAS

X

Related X-Board & Controller Board Connector check

Related X-Board replacement

Module (Panel ) check

85

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Central bottom 4/10 of the screen with vertical bar

Related X-Board power supply voltage check

Related X-Board Connector check

CANVAS

X

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

CANVAS

X

Related X-Board & Controller Board Connector check

Related X-Board replacement

Module (Panel ) check

86

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Top right 3/10 of the screen with vertical bar

Related X-Board power supply voltage check

Related X-Board Connector check

CANVAS

X

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

CANVAS

X

Related X-Board & Controller Board Connector check

Related X-Board replacement

Module (Panel ) check

87

normal

LG Electronics / DND / QA Gr.

Address Bar ( Vertical ) & partial no-picture

Address Bar(Vertical)

CANVAS

X

Top left 3/10 of the screen with vertical bar

Related X-Board power supply voltage check

Related X-Board Connector check

CANVAS

X

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

CANVAS

X

Related X-Board & Controller Board Connector check

Related X-Board replacement

Module (Panel ) check

88

normal

LG Electronics / DND / QA Gr.