Sharp LC-70UD1U Service Manual page 58

LC-70UD1U
• Does not sound.
INPUT-6 No audio.
Is INPUT-6 selected on the input select
menu screen?
NO
Refer to ": No external input
video [INPUT-6]".
YES
Is the audio output selected for "VARI-
ABLE" on the menu screen?
NO
Set the audio output to
"FIXED".
YES
Does the audio signal come from pins (8)
(L) and (7) (R) of input terminal (J510) to
pins (AP34) (L) and (AU36) (R) of IC3301
(CPU)?
NO
Check the line between J510
and IC3301.
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 (1)
INPUT-7 No audio.
Is INPUT-7 selected on the input select
menu screen?
NO
Refer to ": No external input
video [INPUT-7]".
YES
Is the audio output selected for "VARI-
ABLE" on the menu screen?
NO
Set the audio output to
"FIXED".
YES
Does the audio signal come from pins (3)
(L) and (2) (R) of input terminal (J510) to
pins (AR37) (L) and (AT36) (R) of IC3301
(CPU)?
NO
Check the line between J510
and IC3301.
YES
6 – 14
INPUT-5 No audio.
Is INPUT-5 selected on the input select
menu screen?
NO
Refer to ": No external input
video [INPUT-5]".
YES
Is the audio output selected for "VARI-
ABLE" on the menu screen?
NO
Set the audio output to
"FIXED".
YES
Does the audio signal come from pins (13)
(L) and (12) (R) of input terminal (J510) to
pins (AT37) (L) and (AT35) (R) of IC3301
(CPU)?
NO
Check the line between J510
and IC3301.
YES