Read Sharp LC-46DH77E (serv.man5) Service Manual online
LC-42DH77E/RU/S/V, LC-46DH77E/RU/S/V
4 – 9
[External input EXT1, EXT2] No picture on the display (6)
Does not the picture of the R/G/B signal input to EXT1 go out?
Does not the picture of the R/G/B signal input to EXT2 go out?
Does not the picture of the R/G/B signal input to EXT2 go out?
Is RGB1 signal sent to pins (15)/R1, (11)/G1 and (7)/B1 of EXT1
(SC502)?
NO
Check the setting of an external input device that connects with
EXT1.
EXT1.
Is RGB2 signal sent to pins (15)/R2, (11)/G2 and (7)/B2 of EXT2
(SC501)?
(SC501)?
NO
Check the setting of an external input device that connects with
EXT2.
EXT2.
YES
Is RGB1 signal from EXT1(SC502) sent to pins (86)/R1, (82)/G1
and (84)/B1 of IC503 (AV_SW.)?
and (84)/B1 of IC503 (AV_SW.)?
NO
Check the line between SC502 and IC503.
Is RGB2 signal from EXT2 (SC501) sent to pins (92)/R2, (88)/G2
and (90)/B2 of IC503 (AV_SW.)?
and (90)/B2 of IC503 (AV_SW.)?
NO
Check the line between SC501 and IC503.
YES
Is RGB signal output from pins (73)/R_TR, (75)/G_TR and (74)/
B_TR of IC503?
B_TR of IC503?
NO
Check the IC503 and their peripheral circuits.
YES
Is RGB signal sent to pins (T1)/R_TR, (U2)/G_TR, (P3)/B_TR of
IC8101 (DIGITAL AV DECODER & MAIN CPU & VIDEO PRO-
CESSER) from pins (73)/R_TR, (75)/G_TR, (74)/B_TR of IC503?
IC8101 (DIGITAL AV DECODER & MAIN CPU & VIDEO PRO-
CESSER) from pins (73)/R_TR, (75)/G_TR, (74)/B_TR of IC503?
NO
Check the line between IC503 and IC8101.
YES
Refer to “The picture doesn’t appear in all modes.”
[External input EXT3] No picture on the display (7)
Does not the picture of the component video signal input to EXT3 go out?
Is a COMPONENT video signal input to pins (3)/Y, (5)/Pb, (7)/Pr
of EXT3 (J501)?
NO
Check the setting of an external input device that connects with
EXT3.
EXT3.
YES
Is COMPONENT video signal from EXT3 (J501) sent to pins
(94)/Y, (96)/Pb and (98)/Pr of IC503 (AV_SW.)?
(94)/Y, (96)/Pb and (98)/Pr of IC503 (AV_SW.)?
NO
Check the line between J501 and IC503.
YES
Is COMPONENT video signal output from pins (75)/COMP_Y,
(74)/COMP_PB and (73)/COMP_PR of IC503?
(74)/COMP_PB and (73)/COMP_PR of IC503?
NO
Is COMP1_PLUGl detection signal to pin (79) of IC503 input from
pin (2) of EXT3 (J501)?
pin (2) of EXT3 (J501)?
YES
YES
Check the IC503 and their peripheral circuits.
Is COMPONENT signal sent to pins (U2)/COMP_Y, (P3)/
COMP_PB and (T1)/COMP_PR of IC8101 (DIGITAL AV
DECODER & MAIN CPU & VIDEO PROCESSER) from pins
(75)/COMP_Y, (74)/COMP_PB, (73)/COMP_PR of IC503?
COMP_PB and (T1)/COMP_PR of IC8101 (DIGITAL AV
DECODER & MAIN CPU & VIDEO PROCESSER) from pins
(75)/COMP_Y, (74)/COMP_PB, (73)/COMP_PR of IC503?
NO
Check the line between IC503 and IC8101.
YES
Refer to “The picture doesn't appear in all modes”
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