No audio output from external input
<<HDMI>>[INPUT-3]
Is L-ch audio signal fed from input terminal J504 to pin 42 of IC503?
Is R-ch audio signal fed from input terminal J504 to pin 40 of IC503?
<<PC>>[INPUT-4]
Is L-ch audio signal fed from input terminal J401 to pin 7 of IC301?
Is R-ch audio signal fed from input terminal J401 to pin 3 of IC301?
Are audio signals from pins 33 and 34 of IC503 to pins 1 and 4 of
IC302 normal?
<<INPUT-1>>
Is L-ch audio signal fed from input terminal J501 to pin 8 of IC503?
Is R-ch audio signal fed from input terminal J501 to pin 10 of IC503?
<<INPUT-2>>
Is L-ch audio signal fed from input terminal J503 to pin 2 of IC503?
Is R-ch audio signal fed from input terminal J503 to pin 4 of IC503?
No
Check the circuits between IC503 and IC302.
Check the Circuits between IC302 and IC303.
(MUTE circuits:Q301,Q302)
Is audio input from pins 25 and 23 of IC302 to pins 5 and 9 of IC303
normal?
No
Check IC303 and peripheral circuits.
Is audiio output from IC303 normal?
No
Check the connector (P301) of MAIN_UNIT and around the speakers
Yes
Yes
Yes
Yes