LC-42/46/52D85X
6 – 2
The sound is not emitted from the speaker though the picture has come out.
No sound output in all modes?
SUB UNIT:
Is the audio signal output of pins (38) (L-ch) and (39) (R-ch) of
IC1404 (CODEC) normal?
NO
Check IC1404 and its peripheral circuits.
YES
Is audio signal input to pin (5/L), pin (9/R) of IC1301 (AMP)?
NO
Check the line between IC1404 and IC1301.
YES
Is MUTE circuit [SP_MUTE_LINE, S_STBY_LINE] normal?
NO
Check the SP_MUTE_LINE and S_STBY_LINE.
(Q1302, etc.)
YES
Is the audio signal output of pins (2, 1) (L-ch) and (3, 4) (R-ch) 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)
Does not the sound go out though the picture has come out when UHF/VHF is received?
SUB 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 input from pin (24/L-ch), (22/R-ch) 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”.
