Zenith D35, Service Manual

Page: 17 / 156

3-5
2. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
(2) The unstable loading of a Cassette tape
Auto Stop
Does the SW30 waveform
appear at the IC501
Pin24?
Do the T-UP Reel Pulses
appear at the IC501 Pin4?
Is 12V applied to the
PMC01 Pin8?
Check the Drum Motor
signal.
Does 5.2V appear at the
RS501?
Check the Power Circuit.
Check the Power.
Is 5.3V applied to the
R544 ?
Refer to SMPS 5.3VA
troubleshooting.
Check the IC501
Pins74,75, 76, 77.
Do T/UP Reel Pulses
appear at the Q514
Base terminal ?
Replace the T/UP Reel
Sensor (RS501).
Check the CST SW and
the peripheral circuitry.
Replace the IC501.
The unstable loading of a
Cassette tape
Does the “H” signal appear
at the IC501 Pin57 during
inserting the CST ?
Does the “L” signal appear
at the IC501 Pins19, 20
during inserting the CST?
Check the Deck
Mechanism.
Caution : Auto stop can occur because Grease or Oil is dried up
YES
YES
YES
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO NO
YES
YES YES