LG 42PC55 Service Manual page 23

4. No Raster
(1) Symptom
1) No OSD and image occur at screen.
2) It maintains the condition where the front LED is green.
(2) Check following
Does minute discharge
At Module?
Yes
Is the LVDC cable
normal?
Yes
Is the IC700(FLI8548)
Output normal?
No
Is the VAVS on?
YES
Check the PDP Module
No
Reconnect the LVDS
cable in P800
No
Replace the VSC.
NO
Is output the normality
Low/High voltage except
stand-by 5V?
NO
Replace the Power
board