LC-46X8E (serv.man8). Troubleshooting Table - Sharp TV Parts Guide (repair manual). Page 13

LC-46X8E/S/RU

4 – 13

                                            
The Y/C video signal input from EXT1 doesn’t come out in the display.
The Y/C video signal input from EXT2 doesn’t come out in the display.

TERMINAL UNIT:                 
<EXT1>
Is Y/C video signal sent to pins (20, 15) of SCART1 (SC502)?

NO

Check the setting of an external input device that connects of 
SC502.

<EXT2>
Is Y/C video signal sent to pins (20, 15) of SCART2 (SC503)?

NO

Check the setting of an external input device that connects of 
SC503.

YES

<EXT1>
Is Y/C signal sent to pins (67, 69) of IC506?

NO

Check the line between SC502 and IC506.

<EXT2>
Is Y/C signal sent to pins (73, 75) of IC506?

NO

Check the line between SC503 and IC506.

YES

Is Y/C signal output from pins (52, 50) of IC506 to pins (2, 4) of 
connector (SC501)?

NO

Check the line between IC506 and SC501.

MAIN UNIT:                          

YES

Is Y/C signal sent to pins (2, 4) of connector (SC1101)?

NO

Check the connector (SC501/SC1101)

YES

Is Y/C signal sent to pins (Y4, V9) of IC3301 
(VIDEO_PROCESSOR)?

NO

Check the line between SC1101 and IC3301.

YES

Refer to “The picture doesn't appear in all modes.”