Samsung UN HU7250F Series, Service Manual

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4-2-2. No Video (HDMI 1/2/3/4_Digital signal)
Symptom Audio is normal but no picture is displayed on the screen.
Major
checkpoints
Check the HDMI source. •
Check the HDMI switch. •
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 HDMI source and check the
connection of HDMI cable.
No Input the HDMI signal properly.
Yes
1
Check the signal at Input of Main Board.
HDMI1 Clk
-
Pin #10, #12 of CN700
DATA : Pin #7, #9, #4, #6, #1, #3 •
of CN700
HDMI2 Clk
-
Pin #10, #12 of CN701
DATA : Pin #7, #9, #4, #6, #1, #3 •
of CN701
HDMI3 Clk
-
Pin #10, #12 of CN801
DATA : Pin #7, #9, #4, #6, #1, #3 •
of CN801
HDMI4 Clk
-
Pin #10, #12 of CN800
DATA : Pin #7, #9, #4, #6, #1, #3 •
of CN800
No
Check CN700, 701, 800, 801.
Check HDMI cable.
Change the Main Ass'y.
or
Check IC1400(NT14U).
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.
4-7
4. Troubleshooting