Sharp LC-60LE745U Service Manual page 64

LC-60/70LE745U,C7450U,LE845U,C8470U,LE847U (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
Does the digital audio signal come from pins(AR11/AP11/AN9)(CPU_AOBCK/AOLRCK/AOSDATA0) of IC3301(CPU) to pins(6/7/5)(SP_BCLK/
SP_LRCLK/SP_DATA) of IC1703(Audio DSP)?
NO
Check the line between IC3301 and IC1703, and their paripheral circuits.
YES
• About the L/R Speakers.
Does the digital audio signal come from pins (30/21/26/27) of IC1703 (Audio DSP) to pin (5/7/8/6) of IC1902 (AMP for L/R)?
• About the Subwoofer speaker.
Does the digital audio signal come from pins (30/21/26/28) of IC1703 (Audio DSP) to pin (5/7/8/6) of IC1901 (AMP for SW)?
NO
Check IC1703 and its paripheral circuits.(X1701, etc.)
YES
• About the L/R Speakers.
Is the audio output from IC1902 as specified?
• About the Subwoofer Speaker.
Is the audio output from IC1901 as specified?
NO
• About the L/R Speakers.
Check IC1902 and its peripheral circuits.
• About the Subwoofer Speaker.
Check IC1901 and its peripheral circuits.
YES
• About the L/R Speakers.
Check the connector (P1903) L/R speakers and their peripheral circuits.
• About the Subwoofer Speaker.
Check the connector (P1904), subwoofer speaker and their peripheral circuits.
No audio (3)
No audio at digital broadcast signal reception.
Is TV selected on the input select menu screen?
YES
Is the audio output selected for "VARIABLE" on the menu screen?
YES
6 – 19
NO
Refer to "No video at digital broadcast signal
reception".
NO
Set the audio output to "FIXED".