No Audio At Uhf/Vhf Broadcast Signal Reception; No Audio At Digital Broadcast Signal Reception - Sharp LC-52LE640U Service Manual

LC-52/60/70LE640U,C6400U (1st Edition)

No audio at UHF/VHF broadcast signal reception.

Is TV selected on the input select menu screen?
NO
Refer to "No video at UHF/VHF broadcast signal
reception".
YES
Is the audio output selected for "VARIABLE" on the menu screen?
NO
Set the audio output to "FIXED".
YES
Is there the SIF signal output at pin (8) of tuner (TU1105)?
NO
Check the tuner (TU1105) and its peripheral cir-
cuits.
(I2C line: TUNER_SCL/TUNER_SDA, etc.)
YES
Does the SIF signal come from pin (8) of TU1105 (tuner) to pin
(AM24) of IC3303 (CPU)?
NO
Check the line between TU1105 and IC3303, and
their peripheral circuits.
YES
Does the digital audio signal come from pins (Y32/Y31/Y30/V27) (CPU_AOMCLK/AOBCK/AOLRCK/AOSDATA0) of IC3303 (CPU) to pins (5/7/8/6)
(AMP_MCLK/BCLK/LRCLK/DATA_LR) of IC2703 (AMP for L/R)?
NO
Check the line between IC3303 and IC2703 and their peripheral circuits.
YES
Is the audio output from IC2703 as specified?
YES
Check the connector (P2701) L/R speakers and their peripheral cir-
cuits.
No audio (3)

No audio at digital broadcast signal reception.

Is TV selected on the input select menu screen?
YES
If no video appears, refer to "No video at digital broadcast signal
reception".
Is the audio output selected for "VARIABLE" on the menu screen?
YES
NO Check IC2703 and their peripheral circuits.
6 – 17
NO
Refer to "No video at digital broadcast signal
reception".
NO
Set the audio output to "FIXED".