No Sound From External Input Devices - Sharp LC-19D1E/S-BK/WH Service Manual

No sound from EXT1 (SCART) connecting an external input
device.
<EXT1>
Is SCART-L-IN audio signal input from pin (6) of SCART1 termi-
nal (SC501) to pin (14) of IC501 (AV-SW)?
Is SCART-R-IN audio signal input from pin (2) of SCART1 termi-
nal (SC501) to pin (15) of IC501?
Is the audio signal (TERMINAL-L/R) properly output from pins
(34) and (33) of IC501 (AV-SW)?
Is the audio signal (LOUT2/ROUT2) output properly from pins
(25) and (23) of IC302 (A-CODEC) ?
Is the audio signal L-CH output to pins (44-45) and (40-41) of
IC303 (POWER-AMP)? Is the audio signal R-CH output to pins
(20-21) and (16-17) of IC303 (POWER-AMP) normally ?
Is the audio signal of pins (1)-(4) of SP-Connector (P301) prop-
erly output?
Check SP-BOX (right and left) and WIRE HARNESS.

No sound from external input devices (3)-1

YES
YES
YES
YES
YES
Check pins (6) and (2) of SCART1 and connection to an external
input device.
NO
NO Check the Power supply input of pin(38) of IC501, or SDA2/SCL2
signal of pins (28) and (29) or peripheral circuits.
NO Check pins (1) and (4) of IC302 (A-CODEC) , pins (11) and (12)
of Connector SC1202, audio-mute line (Q301/Q302) or periph-
eral circuits.
NO Check UR12V power supply input pins (47) and (14) of IC303
(POWER-AMP) or peripheral circuits.
NO Check SP-CONNECTOR (P301) and short circuit.
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LC-19D1E/S-BK/WH