Samsung LT20A350 - 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 Main Chipset.
- This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
Diagnostics
MAIN BOARDSMPS BOARD
Does the CVBS data appear at
PIN - COMP1_Y_CVBS, COMP2_Y_CVBS?
Does the digital data appear at
TP-E_TXCLK+, E_TXCLK- ,
O_TXCLK+, O_TXCLK-?
Yes
Yes
Yes
Yes
Check a set in the 'Stand-by mode'.
Input the video source properly.
Please, Contact Tech support.
Check CN503.
Change the Main Assy.
Check IC1111 (X5).
Change the Main Assy.
No
No
No
No
No
Power indicator LED is off.
Lamp(Backlight) on, no video ?
Check the video source and
check the connection of video cable?
Check the LVDS cable?
Check the T-Con B'd?
Replace the LCD panel?
4
2
Caution Make sure to disconnect the power before working on the IP board.