No Video_Tuner - Cvbs (X4) - Samsung LA22C450E1 Service Manual

4-1-4. No Video_Tuner - CVBS (X4)

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 Tuner, Check the Chelsea.
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checkpoints
This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
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Diagnostics
Caution Make sure to disconnect the power before working on the IP board.
Power indicator LED is off.
Lamp(Backlight) on, no video ?
Yes
Check the RF source and
check the connection of RF cable ?
Yes
Does the DC B5V_TU_PW, TU33V_PW
appear at #3, #4 Pin of Tuner?
Yes
Does the digital data appear at
TP-E_TXCLK+, E_TXCLK-,
O_TXCLK+, O_TXCLK- ?
Yes
Check the LVDS cable?
Check the T-Con B'd?
Replace the LCD panel?
No
Check a set in the 'Stand-by mode'
No
Input the RF source properly.
No
Change the Main Assy.
Check IC3002 (X4).
No
Change the Main Assy.
No Please, Contact Tech support.
4. Troubleshooting
4-19