No Input-4/5(Hdmi) Audio - Sharp LC-37D44U Service Manual

No INPUT-4/5(HDMI) audio

If no video appears, refer to "No external input video (HDMI)
[INPUT-4/5]".
Is the HDMI_MUTE line as specified?
Check Q1301, IC1302 and their peripheral circuits.
YES
Is there the SPDIF signal (OPT_OUT) output at pin(AP11) of IC8001(CPU)?
Is there the SPDIF signal (OPT_OUT) input at pin(2) of IC1304
(SPDIF_BUFF & MUTE)?
Is there the MUTE signal input at pin(1) of IC1304?
Is there the SPDIF signal input at pin(1) of D1306(OPTICAL OUTPUT)? NO
Check the speakers and their peripheral circuits.
No audio signal at Digital Audio Output terminal (Analog sound heard)
NO
YES
YES
YES
YES
No audio at digital broadcast signal reception
Are there the video signal outputs (IF_OUT_P/N) at the pins(19) and (20)
of tuner(TU1101)?
Check the tuner(TU1101) and its peripheral circuits.
YES
Does the video signal outputs come from pins(19) and (20) of
tuner(TU1101) to AM33 and AM34 of IC8001?
Check the line between TU1101 and IC8001.
YES
Check the IC8001 and its peripheral circuits.
NO Check the line between IC8001 and IC1304.
NO Check the MUTE_A_ALL and ACDET signals, and their
peripheral circuits. (Q1304, Q1312, D1310, etc.)
Check D1306 and its peripheral circuits.
No optical output under the following conditions as per
HDMI requirements.
*Audio contents protected.
*Audio frequency beyond 48kHz.
*Audio bit length beyond 16bits.
6 – 11
LC-37D44U
NO
NO
NO