No Video (Tuner_Cvbs) - Samsung UN HU7250F Series Service Manual

4. Troubleshooting

4-2-3. No Video (Tuner_CVBS)

Symptom Audio is normal but no picture is displayed on the screen.
• Check the Tuner CVBS source.
Major • Check the Tuner.
checkpoints
• This may happen when the LVDS cable connecting the Main Board and the Panel is
disconnected.
1
Diagnostics
1
2
3
Caution Make sure to disconnect the power before working on the IP Board.
4-10
Power indicator LED is off.
Lamp(Backlight) on, no video ?
Yes
Check the RF source and check the
connection of RF cable.
Yes
Check the Power of Tuner.
Pin #4 of Tuner : B1.8V_Tuner
-
Pin #1 of Tuner : B3.3V_Tuner
-
Yes
Check the CVBS data out of IC1400.
L903 : Tuner CVBS_OUT
-
CVBS_OUT_TP : IC1400 CVBS_
-
OUT
Yes
Check the LVDS clk signal at output of
Main Board. (TX)
TX6_CLK : TCON SDA
-
TX8_DATA : TCON SCL
-
Yes
Check the LVDS cable?
Replace the T CON / LCD panel?
No Check a set in the 'Stand-by mode'.
No Input the RF source properly.
No Change the Main Ass'y.
Check IC1400(NT14U).
No
Change the Main Ass'y.
Check IC1400(NT14U).
No
Change the Main Ass'y.
Yes Please, Contact tech support.