Aiwa HV-MC90 Service Manual page 46

ELECTRICAL TROUBLESHOOTING -12/13
5. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
Auto Stop
YES
Does the SW30 waveform
appear at the IC501
Pin 24?
YES
Do the T-UP Reel Pulses
appear at the IC501 Pin 99?
YES
Replace the IC501.
(2) The unstable loading of a Cassette tape
The unstable loading of a
Cassette tape
YES
Is 12V applied to the
IC502 Pin 9?
YES
Does the "H" signal appear
at the IC501 Pin 67 during
inserting the CST ?
YES
Does the "L" signal appear
at the IC501 Pin 53 during
inserting the CST?
YES
Does 6.2V occur at the
IC502 Pin 15 during
inserting the CST?
YES
Check the Deck
Mechanism.
Caution :
Auto stop can occur because Grease or Oil is dried up
NO
Check the Drum Motor
signal.
Do T/UP Reel Pulses
NO
appear at the Q514
Base terminal ?
YES
Replace the T/UP Reel
Sensor (RS501).
NO
NO
Check the CST SW and
the peripheral circuitry.
NO
NO
-46-
NO
Does 5.0V appear at the
RS501?
YES
Check the Q155 Power
Circuit.
Refer to "SMPS CAPSTAN
12 Volt Trouble Shooting".
Is 5.3V applied to the
R544 ?
YES
Refer to SMPS 5.3VA
troubleshooting.
Check the IC501
Pins 32, 33, 34, 35.
Replace the IC502.
NO
NO