Sharp LC-37D90U Service Manual page 91

Check the SC502 and SC1102
connectors.
[INPUT-1] Does the audio signal come from
pins (2) and (4) of SC1102 to pins (53)(L) and
(54)(R) of IC1403 (CODEC)?
[INPUT-2] Does the audio signal come from
pins (10) and (12) of SC1102 to pins (57)(L)
and (58)(R) of IC1403 (CODEC)?
YES
Check the line between SC1102
and IC1403 and their peripheral
circuits.
Is there the audio signal output at pins (38)(L) and (39)(R) of IC1403?
YES
Is there the audio signal output at pins (8)(L) and (11)(R) of connector
(SC1301) on the main unit?
YES
Is there the audio signal input at pins (8)(L) and (11)(R) of connector
(P2704) on the IF unit?
YES
Is there the audio signal input at pins (11)(L) and (15)(R) of IC2701
(STEREO_AMP)?
YES
Is the audio output from IC2701 as specified?
YES
Does the speaker select relay (T2701) function?
YES
Check the connector (P2703), speakers and their peripheral circuits.
NO
Check IC1403 and its peripheral circuits.
NO
Check the line between IC1407 and SC1301.
NO
Check the SC1301 and P2704 connectors.
NO
Check the line between P2704 and IC2701, and their
peripheral circuits (MUTE circuit: Q2701 and AMP_MUTE
NO
line)
Check IC2701 and its peripheral circuits.
NO
Check the SP-RELAY line and its peripheral circuits (Q2702
and SP-RELAY line).
NO
6 – 12
LC-37D90U
YES
NO
Check the line between
IC1508 and IC1403 and their
peripheral circuits.
No audio in all modes (3)