Samsung HG40ED590BB - No Video (Tuner_Cvbs)

4-2-3. No Video (Tuner_CVBS)
Symptom Audio is normal but no picture is displayed on the screen.•
Major
checkpoints
Check the Tuner CVBS source.•
Check the Tuner.•
This may happen when the LVDS cable connecting the Main Board and the Panel is •
disconnected.
Diagnostics
Power indicator LED is off.
Lamp(Backlight) on, no video ?
No
Check a set in the ‘Stand-by mode’.
Yes
Check the RF source and check the
connection of RF cable.
No
Input the RF source properly.
Yes
1
Check the Power of Tuner ?
Pin #29 of Tuner : B3.3V_Tuner
Pin #4 of Tuner : B1.8V_Tuner
No
Change the Main Ass’y.
Yes
2
Check the CVBS data out of IC1001 ?
C807 : Tuner CVBS
No
Check IC1001(X14H).
Change the Main Ass’y.
Yes
3
Check the LVDS clk signal at output of
Main board. (TX)
TX2_CLK : ODD_TXCLK_DN/DP
TX4_CLK : EVEN_TXCLK_DN/DP
No
Check IC1001(X14H).
Change the Main Ass’y.
Yes
Check the LVDS cable?
Replace the T CON / LCD panel?
No
Please, Contact tech support.
Caution Make sure to disconnect the power before working on the IP Board.
4-8
4. Troubleshooting