Samsung LT20A350 - No Video (Tuner DTV)

4-13
4. Troubleshooting
4-1-6. No Video (Tuner DTV)
Symptom
- Audio is normal but no picture is displayed on the screen.
Major
checkpoints
- Check the DTV source.
- Check the Tuner, 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 DC B5V_TU_PW, B33V_TU_PW
appear at #3, #5 Pin of Tuner ?
Check the 'signal strength' in Self Diagnosis
menu Strength is enough ?
Does the digital data appear at
TP-E_TXCLK+, E_TXCLK- ,
O_TXCLK+, O_TXCLK-?
Yes
Yes
Yes
Yes
Yes
Check a set in the 'Stand-by mode'
Input the RF source properly.
Please, Contact Tech support.
Change the Main Assy.
Check the D-TV source.
Check IC1111 (X5).
Change the Main Assy.
No
No
No
No
No
No
Power indicator LED is off.
Lamp(Backlight) on, no video ?
Check the RF source and
check the connection of RF cable ?
Check the LVDS cable?
Check the T-Con B'd?
Replace the LCD panel?
2
Caution Make sure to disconnect the power before working on the IP board.