Zenith XBV243 Service Manual page 16

TROUBLESHOOTING (CONTINUED)
2. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
Auto Stop
YES
Does the SW30 waveform
appear at IC501
Pin24?
YES
Do the T-UP Reel Pulses
appear at IC501 Pin4?
YES
Replace Ic501.
(2) The unstable loading of a Cassette tape
The unstable loading of a
Cassette tape
YES
Is 12V applied to
PMC01 Pin8?
YES
Does the "H" signal appear
at Ic501 Pin57 during
inserting the CST ?
YES
Does the "L" signal appear
at Ic501 Pin19 during
inserting the CST?
YES
Check the Deck
Mechanism.
Caution: Auto stop can occur because Grease or Oil is dried up
VR168 - 923-03485
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ELECTRICAL
NO
Check the Drum Motor
signal.
Do T/UP Reel Pulses
NO
appear at Q514
Base terminal ?
YES
Replace the T/UP Reel
Sensor (RS501).
N O
N O
Check the CST SW and
the peripheral circuitry.
NO
3-4
NO
Does 5.2V appear at
RS501?
YES
Check the Q116 Power
Circuit.
Refer to "SMPS DRUM
12 Volt Trouble Shooting".
Is 5.3V applied to
R544 ?
YES
NO
Refer to SMPS 5.3VA
troubleshooting.
Check IC501
Pins74, 75, 76, 77.
D35E COMBO - ELECTRICAL
NO