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NOTE: Always check for latest ROM/ECO upgrade. If socketed IC is suspected bad, be to check socket with
ohmmeter.
No LED's on power up.
Error LED flashes on power up. Check all RAM and ROM locations.
Error LED stays on all the time. Check 6502 microprocessor.
Drive motor runs continuously
and red LED stays on.
Drive motor runs continuously
and red LED stays off.
Drive motor runs continuously
with no red or green LED's.
After the drive warms up the
motor runs continuously.
Loads programs with red LED
flashing.
Loading is intermittent.
Does not load when hot or LED
flashed 3 times.
Searches with LED flashing
continuously.
Searching with no red LED.
Message 'FILE NOT FOUND'
is displayed
Drive fails to read.
TROUBLESHOOTING GUIDE
SYMPTOM
POSSIBLE SOLUTION
Is Power cord plugged into wall outlet correctly?
Is Power cord plugged in the disk drive correctly?
Check line fuse.
Check power switch.
Check clock on 6502 pin 37.
Check +5 and +12 volt lines.
Check ROMs.
Check +12V.
Check 6502, logic gates, logic array.
Check Rom
Check drive motor PCB.
Check VR2 (5V Regulator)
Check Power Transformer.
Check 6522s.
Check motor control PCB.
Check drive speed.
Check stepper motor.
Check ROMs.
Check drive alignment.
Check ROMs.
Check ROMs.
Check 6522s, logic gates, logic array.
Clean drive head w/alcohol.
Check 0 stop adjustment.
Check alignment.
Check the 311, 9602, and 592s.
There are two +12 volt sources for stepper output
and read circuit, make sure both are good.
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