Samsung UA40B7000WM Service Manual page 48

4. Troubleshooting
4-1-4. No Video (Tuner_CVBS)
Symptom Audio is normal but no picture is displayed on the screen.
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Check the Tuner CVBS source
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Major
Check the Chelsea
-
checkpoints
This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
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Caution Make sure to disconnect the power before working on the IP board.
Diagnostics
6
5
4-14
No video
Yes
Check the RF source and
check the connection of RF cable?
Yes
Does the signal appear at pin8 of
TU5001?
Yes
Does the digital data appear at
pin14~42 of CN7005?
Yes
Check the LVDS cable?
Replace the LCD panel?
No
Input the RF signal.
Check the connected cable.
No
Check TU5001
Change the main PCB assembly.
No
Check IC7001
Change the main PCB assembly.
No
Please, contact Tech support