JVC KD-SX747 Service Manual page 25

3.2.5 Signal processing section
Is the sound output from
both channels (L, R)?
Normal
NO
No sound from either
YES
Is 9V present at IC101 pin
Is the audio signal
(including sampling output
components) output to
IC521 pins ^and | during
Is the audio signal output
at IC101 pins 1
and7during playback?
Check the muting circuit.
NO
channel.
YES
NO
(8)?
YES
NO
YES
NO
YES
Compare the L-ch and
R-ch to locate the
defective point.
Check the vicinity of the
Q981 audio power
supply.
Check IC521 and its
peripheral circuits.
Check IC101 and its
peripheral circuits
(No.49822)1-25
KD-S747