Sharp LC-40LE820UN Service Manual page 73

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 (14) of tuner (TU1102)?
NO
Check the tuner (TU1102) and its peripheral cir-
cuits.
(I2C line: TUNER_SCL/TUNER_SDA, etc.)
YES
Does the SIF signal come from pin (14) of tuner (TU1102) to pin
(AB27) of IC3302 (CPU)?
NO
Check the line between TU1102 and IC3302, and
their peripheral circuits (Q1101, Q1102, etc.).
YES
Does the digital audio signal come from pins (F28/F30/G28) (AUBCK/AULRCK/AOSDATA0) of
IC3302 (CPU) to pin (8/9/7) (SP_BCLK/SP_LRCLK/SP_DATA) of IC2701 (Audio DSP)?
NO
Check the line between IC3302 and IC2701, and
their peripheral circuits.
YES
• About the L/R Speakers.
Does the digital audio signal come from pins (47/43/44/45) of
IC2701 (Audio DSP) to pin (5/8/7/6) of IC2703 (AMP for L/R)?
• About the Subwoofer speaker.
Does the digital audio signal come from pins (47/43/44/46) of
IC2701 (Audio DSP) to pin (5/8/7/6) of IC2702 (AMP for SW)?
YES
• About the L/R Speakers.
Is the audio output from IC2703 as specified?
• About the Subwoofer Speaker.
IS the audio output from IC2702 as specified?
Yes
• About the L/R Speakers.
Check the connector (P2701) L/R speakers and their peripheral cir-
cuits.
• About the Subwoofer Speaker.
Check the connector (P2702), subwoofer speaker and their periph-
eral.
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 IC2701 and its peripheral circuits. (X2701, etc.).
• About the L/R Speakers.
NO
Check IC2703 and its peripheral circuits.
• About the Subwoofer Speaker.
Check IC2702 and its peripheral circuits.
7 – 9
LC-40/46/52/60LE820UN
NO
Refer to "No video at digital broadcast signal
reception".
NO
Set the audio output to "FIXED".