No Sound (During The Reception Of Tv(Analog) Broadcasting); No Sound From External Input Devices - Sharp LC-42SB45U Service Manual

LC-42SB45U
Is the audio signal output of pin (2, 1) (L-ch) and pin (1, 2) (R-ch) of
CN604 & CN605(AOUDIO-CONNECTOR) normal?
Check Speaker (right and left) and wire harness.
Does not the sound go out though the picture has come out when UHF/VHF is received?
↓
TEREMINAL UNIT:
Is the SIF signal output from pin (3) of TUNER (TU201)?
Is the SIF signal sent to pin (P25) and pin (P26) of IC U400?
Refer to "No sound output in all modes".
Does not the sound go out though the picture has come out when DTV is received?
MAIN UNIT:
Is the DIF signal output from pin (18) and pin (19) of TUNER
(TU201)?
Is the DIF signal sent to pin (AB24) and pin (AC24) of IC U400?
Refer to "No sound output in all modes".
Does not the sound of the audio signal input to INPUT 1(Component) go out?
Does not the sound of the audio signal input to INPUT 2(Component) go out?
MAIN UNIT:
Is the audio signal properly sent to pin (2) (AV1_AudioLIN) and pin
(4)(AV1_AudioRIN) of CN552?
Is the audio signal properly sent to pin (2) (AV2_AudioLIN) and pin
(4)(AV2_AudioRIN) of CN551?
Is the audio signal properly sent to pin (J23) (AV1_LIN) and pin
(J24) (AV1_RIN) of IC U400?
Is the audio signal properly sent to pin (J25) (AV2_LIN) and pin
(J26) (AV2_RIN) of IC U400?
Refer to "No sound output in all modes".
↓YES

No sound (during the reception of TV(ANALOG) broadcasting)

↓
↓YES
↓YES
No sound (during the reception of TV (DIGITAL) broadcasting)
↓
↓
↓YES
↓YES

No sound from external input devices (1)

↓
↓
↓YES
↓YES
NO
Check IC U600 and its peripheral circuits.
NO
Check the tuner and its peripheral circuits. Replace as required.
NO Check IC U400 its peripheral circuits.
NO
Check the tuner and its peripheral circuits. Replace as required.
NO
Check IC U400 its peripheral circuits.
Check the connection to CN552 and the external input device.
NO
Check the connection to CN551 and the external input device.
Check the line between CN552 and IC U400.
NO
Check the line between CN551 and IC U400.
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