Picture Problem; No Picture/Sound Ok - LG 42PJ350R Service Manual

Repair Process
PDP TV
Symptom
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 Module pattern
by using "TILT" key
Normal
on SVC R/C
Check
Vs, Va
<SVC R/C & Pattern>
A. Picture Problem

No Picture/Sound OK

Check
Y
Sound
Sound OK
Move
N
No Picture/No sound
Section
Check voltage
Y
. -V
Y
Normal
. V
SC
. V
ZB
N
Move
1. Check Y-Sus/ Z-Sus Board
Power problem
Section 2. Replace defective B/D
※Refer to the Module label for each voltage
-V
Y
Revision
Check
Y
Normal
LVDS Cable
N
Replace
Main B/D
Check B+ Voltage
Y
on Power Board
Normal
/ Control Board
.Check B+(5V)
N
V V
SC ZB
1
Making
Y
Close
N
1.Check Control Board
. LED on
. Crystal(X400)
Y
Normal
. 1.8V, 3.3V,1.2V 5V FET
. Rom update
2.Replace Control B/D
N
Move
Power problem
Section
ⓒ LG Electronics. Inc.2009