Sharp LC-42XL2S Service Manual page 105

LC-42XL2E/S/RU, LC-46XL2E/S/RU, LC-46X20E/S/RU, LC-52XL2E/S/RU, LC-52X20E/S/RU
The audio signal of MONITOR 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 (1/L-ch) and (12/R-ch) of IC7510?
Is audio signal sent to pins (40/L-ch) and (41/R-ch) of IC1404
(CODEC)?
Check IC1404 and its peripheral circuits.
No audio signal output from AUDIO_OUTPUT terminal.
TEREMINAL UNIT:
Is audio signal output to pin (4/L-ch), (2/R-ch) of audio output ter-
minal J503?
Do pin (72)] of MONITOR_MUTE_LINE [IC506
(VIDEO_SELECTOR), pin (55)] of MUTE-A_ALL_LINE
[MAIN_UNIT IC2002 (UCON) become H?
Is the audio signal output of pins (40/L-ch) and (41/R-ch) of
IC1404 (CODEC)?
Check IC1404 and its peripheral circuits.
The audio signal is not output (3)
NO
NO
NO
NO
NO
The audio signal is not output (4)
NO
NO
NO
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 IC1404.
(IC1405, etc.)
YES Check the connection to J502 and external devices.
YES Check the IC506,IC2002, its peripheral circuit and
MONITOR_MUTE_LINE, MUTE-A_ALL_LINE.
(Q512, Q511, D551, etc.)
YES Check the line between IC1404 and J503.
(IC1405, Q509, Q510, etc.)
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