The Audio Signal Is Not Output - Sharp LC-32X20E Service Manual

LC-32X20E/S/RU, LC-37X20E/S/RU
The audio signal of UHF/VHF and DTV is not output from EXT1 (SCART).
TEREMINAL UNIT:
Is audio signal sent to pins (3/L-ch) and (1/R-ch) of SCART1
(SC502)?
Is S-MUTE-LINE [MAIN_UNIT pin (93) of IC9101 (CPLD)] at H?
Is audio signal sent to pins (24/L-ch) and (22/R-ch) of IC1402
(SOUND MULTIPLEX DECODER)?
Check IC1402 and its peripheral circuits.
The audio signal of UHF/VHF and DTV is not output from EXT2 (SCART).
TEREMINAL UNIT:
Is audio signal sent to pins (3/L-ch) and (1/R-ch) of SCART2
(SC503)?
Is S2-MUTE-LINE [MAIN_UNIT pin (91) of IC9101 (CPLD)] at H?
Is audio signal sent to pins (3/L-ch) and (13/R-ch) of IC7510
(SW)?
Is audio signal input to pins (2/L-ch) and (15/R-ch) of IC7510?
Is audio signal sent to pins (24/L-ch) and (22/R-ch) of IC1402
(SOUND MULTIPLEX DECODER)?
Check IC1402 and its peripheral circuits.

The audio signal is not output (1)

NO
NO
NO
The audio signal is not output (2)
NO
NO
NO
NO
NO
YES Check the connection to SCART1 and external devices.
YES Check the peripheral circuits of IC9101 and S-MUTE_LINE.
(Q502, Q504, etc.)
YES Check the line between SC502 and IC1402.
(Q508, Q507, IC1407, etc.)
YES Check the connection to SCART2 and external devices.
YES Check the peripheral circuits of IC9101 and S2-MUTE_LINE.
(Q501, Q503, etc.)
YES Check the line between IC7510 and SC503.
(Q506, Q505, etc.)
YES Check IC7510 or peripheral circuits.
(SC_AUD_SEL_LINE, etc.)
YES Check the line between IC7510 and IC1402.
(IC1407, etc.)
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