Sharp LC-46X8E/S/RU, Service Manual

Page: 42 / 166

LC-46X8E/S/RU
4 – 2
The sound is not emitted from the speaker though the picture has come out.
No sound output in all modes.
TERMINAL UNIT:
Is the audio signal (L/R) output from pins (38, 39) of IC1404
(CODEC) normal?
NO Check IC1404 and its peripheral circuits.
YES
Is audio signal (L/R) input to pin (5, 9) of IC1301 (AMP)? NO Check the line between IC1404 and IC1301.
YES
Is MUTE circuit [SP_MUTE_LINE, S_STBY_LINE] normal? NO This signal is usually “L”.
Check the SP_MUTE_LINE and S_STBY_LINE.
(Q1302, etc.)
YES
Is the audio signal (L/R) output from pins (1, 2) and pins (3, 4) of
P1301 (AOUDIO-CONNECTOR) normal? NO Check IC1301 and its peripheral circuits.
YES
Check Speaker Box (right and left) and wire harness.
No sound (during the reception of TV(ANALOG) broadcasting)
The sound does not come out though the picture come out when UHF\VHF is received.
TERMINAL UNIT:
Is the IF signal output from pin (17) of TUNER (TU7501)?
NO Check the tuner and its peripheral circuits.
Replace as required.
YES
Is the SIF signal sent to pins (23) and (24) of IC7504 (IFDE-
MOD)? NO Check FL7501 and its peripheral circuits.
YES
Is the SIF signal input from pin (12) of IC7504 to pin (3) of IC1402
(SOUND MULTIPLEX DECODER)? NO Check the line between IC7504 and IC1402.
(Q7504, etc.)
YES
Is audio signal (L/R) input from pin (24, 22) of IC1402 to pin (61,
62) of IC1404 (CODEC)? NO Check the line between IC1402 and IC1404.
YES
Refer to “No sound output in all modes”.