Samsung LN40A550P3F - No Video (Video CVBS)

4-16
4. Troubleshooting
4-1-7. No Video (Video CVBS)
Symptom Audio is normal but no picture is displayed on the screen.-
Major
checkpoints
Check the Video CVBS source
Check the MT5382
This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
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Diagnostics
Check CN7002 or Side-AV
Change the main PCB ass’y or
Side-AV assembly
No
Yes
Power Indicator is off.
Lamp on, no video
Yes
Check the video source and
check the connection of
video cable?
No
Input a video signal.
Check the connected cable.
Yes
Check the LVDS cable?
Replace the LCD panel?
Please, Contact 1 800 Samsung
No
Does the digital data appear at output
of R721~R740,R788~R791?
No
Check IC400
Change the main PCB assembly
6
6
Does the signal appear at
C702 of IC400?
Yes
Does the digital data appear at output
of R1109, R1110, R1113P, R1114P,
R1116P, R1120P, R1122~R1128,
R1133, R1135, R1137P~R1141P,
R1143~R1150?
No
Check IC400
Change the main PCB assembly
7
Yes
Caution Make sure to disconnect the power before working on the SMPS board.