Commodore 1541-II User Manual page 18

TROUBLESHOOTING GUIDE
Symptom
Cause
Program's won't load, and
computer says "DEVICE
NOT PRESENT ERROR.''
Programs won't load, but
computer and disk drive
give no error message.
Serial bus cable
not well connected, or
disk not turned on.
Another device on the
serial bus may be
interfering.
Be sure serial bus cable
is correctly inserted
and disk drive is turned
on
Unplug all other devices
on the serial bus. If
that cures it, plug them
in one at a time. The
one just added when the
trouble repeats is most
likely the problem.
Also, trying to load a
machine language program
into BASIC space will
cause this problem.
(Such devices may not be turned on properly, or may have conflicting device numbers. Only one
device on the bus can have any one device number.)
Programs won't load
and disk error light
flashes.
A disk error has
occurred.
Check the disk error
channel to see why the
error occurred. Follow
the advice in Appendix B
to correct it.
(Be sure to spell program names exactly right, as the disk drive is very particular, even about spaces
and punctuation marks, and will not load a program unless you call it exactly the same thing it was
called when it was saved on the diskette.)
Your own programs Load
fine, but commercial
programs and those
from other 1541 owners
fail to load.
Either the diskette you
are loading is faulty,
(some mass-produced
diskettes are) or your
disk drive is misaligned.
Try another copy of the
troublesome programs. If
several programs from
several sources always
fail to load, have your
dealer align your
disk drive.
Your own programs that
used to Load won't
any more, but programs
saved on newly-formatted
diskettes still work.
Older diskettes have
been damaged.
The disk drive has gone
out of alignment.
See the section on safety
rules for diskette care.
Recopy from backups.
Have your dealer align
your disk drive.
The disk drive powers
up with the activity
light blinking.
Hardware failure (RAM,
ROM, PCB).
Have your dealer send it
out for repair.
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