Aiwa HV-MC90 Service Manual page 45

ELECTRICAL TROUBLESHOOTING -11/13
3. Y/C CIRCUIT
(3) No sound in REC Mode,
No sound in REC Mode,
YES
Sound is not recorded.
YES
Is Playback O.K.?
YES
Is the Audio signal applied
to the IC301 Pin 9?
YES
Does the Audio waveform
appear at the IC301 Pin 4 ?
YES
Is 5V applied to the FL301
Pin 5 ?
YES
Is 3.0~4.5V applied to the
Collector of the Q301 ?
YES
Does the Erase signal
appear at the FL301 Pin 2?
NO
Refer to "No sound in PB
Mode,".
NO
Check the path of Line
Audio.
NO
Is the "High" signal applied
to the IC301 Pin 99?
Check the IC501 Pin 55
(Audio Mute "H").
NO
Check the line of the 5V
Power Circuit.
NO
Check the Audio R/P/E
connector and Head.
NO
Replace the FL301 or the
Q301.
NO
YES
-45-
Check the CLK/Date line
and replace the IC301