Sharp LC-22LE320 Service Manual page 78

LC-19LE320, LC-22LE320, LC-26LE320, LC-32LE320, LC-37LE320, LC-42LE320
No sound output in all modes?
TEREMINAL UNIT:
Is the audio signal output of pin (U36)(AR3), (V37)(AL3) of IC U401
normal?
Is audio signal input to pin (4)(LINN), pin (11)(RINN) of IC U601
(AMP)?
Is MUTE circuit [ Shutdown, OFF_MUTE] normal?
Is the audio signal output of pin (3, 4) (L-ch) and pin (1, 2) (R-ch) of
CN601 (AOUDIO-CONNECTOR) normal?
Check Speaker Box (right and left) and wire harness.
Does not the sound go out though the picture has come out when TV is received?
MAIN UNIT:
Is the IF signal output from pin (16) and pin (17) of TUNER
(TU102)?
Is the IF signal sent to pin (AH35) and pin (AH37) of IC U401?
Refer to "No sound output in all modes".
The sound is not emitted from the speaker though the picture has come out.
↓
↓
↓YES
↓YES
↓YES
↓YES
No sound (during the reception of TV broadcasting)
↓
↓
↓YES
↓YES
NO Check IC U401 and its peripheral circuits.
NO
Check the line between IC U605 and IC U601.
NO
Check the Mute circuit. (Q601, Q602 etc.)
NO
Check IC U601 and its peripheral circuits.
NO
Check the tuner and its peripheral circuits. Replace as required.
NO
Check IC U401 its peripheral circuits.
78