Sharp LC-37D90U Service Manual page 93

Are the audio signal inputs at
pins (61)(L) and (62)(R) of
IC1403?
YES
Are the audio signal outputs
at pins (38)(L) and (39)(R) of
IC1403?
YES
Are the audio signal outputs
at pins (8)(L) and (11)(R) of
connector (SC1301) on the
main unit?
YES
Are the audio signal inputs at
pins (8)(L) and (11)(R) of con-
nector (P2704) on the IF unit? NO
YES
Are the audio signal inputs 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 P2703 connector,
speakers and their peripheral
circuits.
Check the line between
IC8801 and IC1403, and
NO
their peripheral circuits.
Check IC1403 and its
peripheral circuits.
NO
Check the line between
IC1407 and SC1301, and
NO
their peripheral circuits.
Check the SC1301 and
P2704 connectors.
Check the line between
P2704 and IC2701, and
NO
their peripheral circuits
(MUTE circuit: Q2701 and
AMP_MUTE line).
Check IC2701 and its
peripheral circuits.
NO
Check the SP-RELAY line
and its peripheral circuits
NO
(Q2702 and SP-RELAY
line).
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LC-37D90U