No Sound From External Output Device - Sharp LC-60LE740E Service Manual

LC-60/70LE740E/RU,741E/S,743E,60LE840E/RU,841E/S,843E,80LE645E/RU,646E/S,648E
Does not the sound of the audio signal input to HDMI1/2/3/4 go out?
Please Refer to "[External input HDMI-1/2/3/4] No picture on the display (11)".
No audio signal output to EXT1 terminal.
Do audio signals output from pins [1/AUDIO_OUT_R, 3/
AUDIO_OUT_L] of EXT1 (SC505)?
Is AUDIO_MUTE(MUTE_A_ALL) [23 pin] of IC2001 (UCOM) at
"H"?
Do audio signals output from pins [1/TUNER_R_OUT, 7/
TUNER_L_OUT] of IC2706 (Buffer AMP)?
Do audio signals input to pins [2, 6] of IC2706?
Do audio signals (TUNER_OUTR/L) output from pins [AG31/
TUNER_OUT_R, AG32/TUNER_OUT_L] of IC3303 (Digital AV
decode & Main CPU)?
Check IC3303 and its peripheral circuits.
No sound from external input devices (5)

No sound from external output device (1)

NO
NO
NO
NO
NO
YES Check the setting of an external input device that connects with
EXT1.
YES Check the peripheral circuits of IC2001 and AUDIO_MUTE.
(Q502 etc...)
YES Check the line between IC2706 and SC505.
YES Check IC2706 and its peripheral circuits.
YES Check between IC3303 and IC2706.
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