Samsung UN40D5500RF - No Video_Tuner - CVBS

4-10
4. Troubleshooting
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, Check the Chelsea. -
This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected. -
Diagnostics
Main Assy
1 B5V 2 SW_PW
3 B5V 4 A5V
5 GND 6 GND
7 B12VS 8 GND
9 B12VS 10 SW_INV
11 B13V 12 NC
13 B13V 14 DMM
Power Assy
1 B5V 2 SW_PW
3 B5V 4 A5V
5 GND 6 GND
7 B12VS 8 GND
9 B12VS 10 SW_INV
11 B13V 12 NC
13 B13V 14 DMM
Main Ass’y
14p cable
Speaker
Power Ass’y
LVDS cable
T-con
Does the DC B1.8V B3.3V
appear at #3, #5 Pin of Tuner ?
Check the CVBS data
at #15 Pin of Tuner ?
Does the digital data appear at
TP-E_TXCLK+, E_TXCLK- ,
O_TXCLK+, O_TXCLK- ?
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.
Change the Main Assy.
Check IC1001 (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 ?

Yes
Yes
Check external devices and
connections.
No
check the Self Diagnosis
(SupportSelf DiagnosisPicture Test)
Dose the promblem still exist self diagnosis ?
Caution Make sure to disconnect the power before working on the IP board.