(No.MA057B)1-29
5.5
Signal processing section
No sound from either
channel.
Is 9V present at IC161
pin 40?
Compare the L-ch and
R-ch to locate the
defective point.
Is the sound output from
both channels (L, R)?
NO
YES
Is the audio signal
(including sampling
output components)
output to IC581 pins 1
and 7 during playback?
Is the audio signal
output at IC161 pins 36
to 39 during playback?
Normal
NO
YES
NO
Is 9V present at IC901
pin 10?
YES
Check the connection
between IC901 pin10
and IC161 pin40.
Check IC901 and its
peripheral circuits.
NO
YES
NO
Check IC581 and its
peripheral circuits.
YES
NO
Check IC161 and its
peripheral circuits.
Check the power amp.
IC301.
YES
Is the audio signal output
at IC301 pins 17and 21
during playback?
YES
NO
Check IC301 and its
peripheral circuits.