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4-16
4. Troubleshooting
4-1-7. No Video (Video CVBS)
Symptom
-
Audio is normal but no picture is displayed on the screen.
Major
checkpoints
-
Check the Video CVBS source
-
Check the Main Chipset.
-
This may happen when the LVDS cable connecting the Main Board and the Panel is disconnected.
Diagnostics
MAIN BOARD
SMPS BOARD
Does the CVBS data appear at
PIN - COMP1_Y_CVBS, COMP2_Y_CVBS?
Does the digital data appear at
TP-, E_TXCLK- ,
, O_TXCLK-?
Yes
Yes
Yes
Yes
Check a set in the 'Stand-by mode'.
Input the video source properly.
Please, Contact Tech support.
Check CN503.
Change the Main Assy.
Check IC1111 (X5).
Change the Main Assy.
No
No
No
No
No
Power indicator LED is off.
Lamp(Backlight) on, no video ?
Check the video source and
check the connection of video cable?
Check the LVDS cable?
Check the T-Con B'd?
Replace the LCD panel?
4
2
Caution
Make sure to disconnect the power before working on the IP board.
Содержание LT20A350
Страница 34: ...4 5 4 Troubleshooting Main Board_Top Main Board_Bottom...
Страница 35: ...4 6 4 Troubleshooting WAVEFORMS 1 PC input V sink H sink R G B 2 LVDS output...
Страница 37: ...4 8 4 Troubleshooting Main Board_Top Main Board_Bottom...
Страница 38: ...4 9 4 Troubleshooting WAVEFORMS 3 HDMI input RX_Data RX_Clk 2 LVDS output...
Страница 40: ...4 11 4 Troubleshooting Main Board_Top Main Board_Bottom...
Страница 41: ...4 12 4 Troubleshooting WAVEFORMS 2 LVDS output...
Страница 43: ...4 14 4 Troubleshooting Main Board_Top Main Board_Bottom...
Страница 44: ...4 15 4 Troubleshooting WAVEFORMS 2 LVDS output...
Страница 46: ...4 17 4 Troubleshooting Main Board_Bottom Main Board_Bottom...
Страница 47: ...4 18 4 Troubleshooting WAVEFORMS 4 CVBS OUT Grey Bar 2 LVDS output...
Страница 49: ...4 20 4 Troubleshooting Main Board_Bottom Main Board_Bottom...
Страница 50: ...4 21 4 Troubleshooting WAVEFORMS 5 Compnent_Y Gray scale Pb Pr Color bar 2 LVDS output...
Страница 53: ...4 24 4 Troubleshooting WAVEFORMS 7 Speaker out...
Страница 70: ...4 41 4 Troubleshooting TOP BOTTOM...
Страница 72: ...4 43 4 Troubleshooting Model Inch CODE P N 24 27 BN44 00450A PD27A0_BDY...