Samsung UN HU7250F Series, Service Manual

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4-2-4. 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. •
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
Check the ‘signal strength’ in Self
Diagnosis menu Strength is enough.
No Check the DTV source.
Yes
1
Check the Power of Tuner.
Pin #4 of Tuner : B1.8V_Tuner
-
Pin #1 of Tuner : B3.3V_Tuner
-
No Change the Main Ass'y.
Yes
2
Check the LVDS clk signal at output of
Main Board. (TX)
TX6_CLK : TCON SDA
-
TX8_DATA : TCON SCL
-
No
Check IC1400(NT14U).
Change the Main Ass’y.
Yes
Check the LVDS cable?
Replace the T CON / LCD panel?
Yes Please, Contact tech support.
Caution Make sure to disconnect the power before working on the IP Board.
4-13
4. Troubleshooting