External Input Ext1 - No Picture On The Display - Sharp LC-40LE820E Service Manual

Is CVBS signal sent to pin (14) of EXT1 (SC505)?
Is CVBS signal from EXT1 (SC505) sent to pin (AG29/
SC1_CVBS_Y) of IC3302 (Digital AV decode & Main CPU)?
Refer to "The picture doesn't appear in all modes."
Is Y/C video signal sent to pins (14)/Y and (4)/C of EXT1
(SC505)?
Is Y/C signal from EXT1 (SC505) sent to pins (AG29/
SC1_CVBS_Y) and (AG28/SC1_C1) of IC3302 (Digital AV
decode & Main CPU)?
Refer to "The picture doesn't appear in all modes."
Is RGB1 signal sent to pins (4)/RGB_IN_RED/C, (6)/
RGB_IN_GREEN and (8)/RGB_IN_BLUE of EXT1 (SC505)?
Is RGB1 signal from EXT1 (SC505) sent to pins (AH22/RED1),
(AJ22/GREEN_1) and (AJ21/BLUE_1) of IC3302 (Digital AV
decode & Main CPU)?
Refer to "The picture doesn't appear in all modes."
[External input EXT1] No picture on the display (4)
Does not the picture of the CVBS signal input to EXT1 go out?
YES
YES
[External input EXT1] No picture on the display (5)
Does not the picture of the Y/C video signal input to EXT1 go out?
YES
YES
[External input EXT1] No picture on the display (6)
Does not the picture of the R/G/B signal input to EXT1 go out?
YES
YES
LC-40/46/52LE820E, LC-40/46LU820E
NO Check the setting of an external input device that connects with
EXT1.
NO Check the line between SC505 and IC3302.
NO Check the setting of an external input device that connects with
EXT1.
NO Check the line between SC505 and IC3302.
NO Check the setting of an external input device that connects with
EXT1.
NO Check the line between SC505 and IC3302.
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