LG 42PQ301R-ZB (CHASSIS:PP91B) Service Manual ▷ View online
Making
Repair Process
Revision
2009. 2 . 1
1/9
PDP TV
Symptom
A. Picture Problem
No Picture/Sound OK
1
Check Module pattern
by using “TILT” key
on SVC R/C
by using “TILT” key
on SVC R/C
Normal
☞A1
N
Check
Vs, Va
Y
Normal
N
Check voltage
. -V
Y
. V
SC
. V
ZB
※Refer to the Module label for each voltage
Y
N
1. Check Y-Sus/ Z-Sus Board
2. Replace defective B/D
2. Replace defective B/D
Check B+ Voltage
on Power Board
on Power Board
/ Control Board
.Check B+(5V)
Y
1.Check Control Board
. LED on
. Crystal(X101)
. 1.8V, 3V, 5V FET
. Rom update
. Crystal(X101)
. 1.8V, 3V, 5V FET
. Rom update
2.Replace Control B/D
☞A3
☞A5~A6
<SVC R/C & Pattern>
Check
Sound
Sound
Sound
OK
Y
Close
Y
Move
No Picture/No sound
Section
☞A2
Check
LVDS Cable
Replace
Main B/D
Normal
N
Y
N
Move
Power problem
Section
Normal
Normal
Move
Power problem
Section
N
☞A4
-V
Y
V
SC
V
ZB
☞A8~A11
☞A12
☞A13
First of all, Check whether all of cable between board was inserted properly or not.
(Main B/D↔ Power B/D, Power B/D↔ Y-sus B/D,Y-Sus B/D ↔Z-Sus B/D,LVDS Cable,Speaker Cable,IR B/D Cable,,,)
Check IR operation
Power
LED ON?
Latest S/W update
from GCSC
(Firmware Management)
N
Y
OSD
appear?
Y
N
Y
N
Close
☞A26
Making
Revision
2009. 2 . 1
2/9
PDP TV
Symptom
A. Picture Problem
No Picture/No Sound
Repair Process
Check Module pattern
by using “TILT” key
on SVC R/C
Normal
☞A1
N
Check
Sound
Sound
OK
Y
☞A2
N
Move
No Picture/ Sound Ok
Section
Close
Y
Check
LVDS Cable
Replace
Main B/D
Normal
Y
N
Replace
Main B/D
Normal
Check Input signal
. RF Cable connection
. SCART Cable connection
. HDMI Cable connection
. Component Cable …
. RF Cable connection
. SCART Cable connection
. HDMI Cable connection
. Component Cable …
2
Normal
Y
N
Repair/Replace
IR B/D
Making
Revision
2009. 2 . 1
3/9
PDP TV
Symptom
A. Picture Problem
Mal-discharge/Noise/dark picture
Repair Process
Y
N
N
☞A15
Mal-discharge
☞A14
Dot
type
Check CTRL ROM Ver.
and
Rom Upgrade
Normal
Picture?
Y
Close
Replace
Control board
Normal
Picture?
Y
Close
Replace
Module
N
Scan
Type
Type
Check
Picture problem
Type
Check voltage
. –V
Y
/ V
SC
(Y-Sus B/D)
☞A5~A6
Normal
Picture?
Replace
Y-Sus B/D
Normal
Picture?
Y
N
1.Check Control B/D
2.Replace Board
2.Replace Board
Normal
Picture?
☞A13
Check
Y Drive B/D
&
Replace B/D
Y
Close
N
Dark Picture
Normal
Picture?
Y
Replace
Module
N
Close
1. Check Z-Sus Board
2. Replace Board
2. Replace Board
☞A9
(42G2)
,A11
(50G2)
Check
Picture mode
setting
Picture Noise
Normal
Picture?
Y
N
Close
Y
N
Check RF Cable
Connection
Connection
Check Tuner
& Replace
& Replace
Normal
Picture?
※Check Discharge resistance (10Ω 2~3ea)
on Power B/D before replace Y Drive B/D
Close
Close
☞A17
3
☞A16
Making
Revision
2009. 2 . 1
4/9
PDP TV
Symptom
A. Picture Problem
Picture broken/Freezing
Repair Process
Y
N
☞A21
4
N
Check RF Signal level
Normal
Signal?
Check RF Cable
Connection
1. Reconnection
2. Install Booster
Check
S/W Version
Booster menu
On→Off: Check
Off→On: Check
Off→On: Check
S/W Upgrade
Check whether other equipments have problem or not.
(By connecting RF Cable at other equipment)
(By connecting RF Cable at other equipment)
→ DVD Player ,Set-Top-Box, Different maker TV etc
SVC
Bulletin?
Replace
Main B/D
Check
Tuner soldering
Normal
Picture?
Y
N
Y
Close
Normal
Picture?
Y
Close
■ Menu→Setup →Booster
. By using Digital signal level meter
. By using Diagnostics menu on OSD
. By using Diagnostics menu on OSD
( Menu→Setup→Diagnostic)
- Signal strength (Normal : over 50%)
- Signal Quality (Normal: over 50%)
- Signal strength (Normal : over 50%)
- Signal Quality (Normal: over 50%)
Normal
Picture?
Y
Contact with signal distributor
or broadcaster (Cable or Air)
N
N
Normal
Picture?
Y
Close
N
※ ’09 years new model apply chip tuner
so, chip tuner is soldered on main PCB
[ Chip Tuner: IC500(XC5000) ]
[ Chip Tuner: IC500(XC5000) ]
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