JVC KD-G815 Service Manual page 30

5.5 Signal processing section
Is the sound output from
both channels (L, R)?
YES
Normal
1-30 (No.MA170)
NO
No sound from either
channel.
YES
Is 9V present at IC161
pin 40?
YES
Is the audio signal
(including sampling
output components)
output to IC572 pins 1
and 7 during playback?
YES
Is the audio signal
output at IC161 pins 36
to 39 during playback?
YES
Is the audio signal output
at IC361/IC381 pins 12
and 13 during playback?
YES
Check the power amp.
IC301.
Compare the L-ch and
NO
R-ch to locate the
defective point.
NO
Is 9V present at IC901
pin 13?
YES
Check the connection
between IC901 pin13
and IC161 pin 40.
NO
Check IC572 and its
peripheral circuits.
NO
Check IC161 and its
peripheral circuits.
NO
Check IC361/IC381 and
its peripheral circuits.
NO
Check IC901 and its
peripheral circuits.