Aiwa HV-MC90 Service Manual page 40

ELECTRICAL TROUBLESHOOTING -6/13
3. Y/C CIRCUIT
(1) No Video in EE Mode,
No Video in EE Mode
Does the Video signal
appear at the IC301 Pin 31?
Is 5V applied to the IC301
Pins 12, 36, 61, 67, 90, 96?
Does the Video signal
appear at the IC301 Pin 52?
Does the Video signal
appear at the Emitter
terminal of the Q3M1?
NO
YES
NO
YES
NO
YES
NO
Check the Video Input
Jack.
(Line In Jack)
Check the 5V Line.
(Power Circuit)
Is I 2 C BUS signal applied to
the IC301 Pins 62, 63?
YES
Is there 13VA on the plus
terminal of the C3M5?
Replace the Q3M1.
-40-
Check the System Circuit.
NO
(Refer to 'SYSTEM I
CHECK Trouble Shooting')
Check C330. (AGC)
NO
Replace the IC301.
Check the 13VA Line.
(Power Circuit)
2 C BUS
YES