Sharp LC-42D65U Service Manual page 52

LC-42D65U
No audio at UHF/VHF broadcast signal reception.
Is TV selected on the input select menu screen?
Is the audio output selected for "VARIABLE" on the menu
screen?
Set the audio output to "FIXED".
YES
Is there the SIF signal output at pin(15) of tuner(TU1101)?
Check the tuner(TU1101) and its peripheral circuits.
YES
Does the SIF signal come from pin(15) of tuner(TU1101) to pin(AN23) of
IC8001(CPU)?
Check the line between TU1101 and IC8001, and their
peripheral circuits. (Q1101, Q1102, etc.)
YES
Does the audio signal come from pins(AP28/AN28)(SPOUT_LN/P), and (AN29/AP29) to pins(6/5)(INLM/INLP), and (8/9)(INRM/INRP) of
IC2701(AMP)?
Is the audio output from IC2701 as specified?
Check the connector(P2701), speakers and their peripheral circuits.
No audio (3)
NO
NO
NO
YES
YES
No audio at digital broadcast signal reception.
Is TV selected on the input select menu screen?
Is the audio output selected for "VARIABLE" on the
menu screen?
Set the audio output to "FIXED".
YES
Are there the video signal outputs (IF_P/N) at the pins(19) and (20)
of tuner(TU1101)?
Check TU1101 and its peripheral circuits. (SDA3/
SCL3, etc.)
YES
Are there the video signal inputs at pin(AM33) and (AM34) of
IC8001(CPU)?
Check the line between TU1101 and IC8001, and
their peripheral circuits. (L1101, C1103, etc.)
YES
Check the line between IC8001 and IC2701, and
their peripheral circuits. (Q1306 thru Q1308,
AMP_MUTE line, etc.)
NO Check IC2701 and its peripheral circuits.
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NO
NO
NO
NO