User`s guide
TROUBLESHOOTING GUIDE
Symptom
Prograrlls won't load, and
computer says
"Dl;lVICE
NOT PRESENT ERROR ."
Programs won't load, but
computer and disk drive
give no error message.
Cause
Serial
bus cable
not well connected,
or
disk not turned on.
Anolher device on the
serial bus may be
interfering.
Remedy
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 A disk error has
and disk error light occurred.
flashes.
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 Either the diskette you
fine, but commercial are loading is faulty,
programs and those (some mass-produced
from other
1541
owners diskettes are)
or
your
fail to load. disk drive
is
misaligned.
Your own programs Iha!
used IQ Load won't
any more, but programs
saved on newly-formatted
diskettes still work.
The disk drive powers
up with the activity
light blinking.
Older diskettes have
been damaged.
The disk drive has gone
out
of
alignment.
Hardware failure (RAM,
ROM, PCB).
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Try another copy
of
the
troublesome programs.
If
several programs from
several sources
always
~
fail to load, have your
dealer align your
disk drive.
See the section on safety
rules for diskette care.
Recopy from backups.
Have your dealer align
your disk drive.
Have your dealer send it
out for repair.
SIMPLE MAINTENANCE TIPS
Your 1541 should serve you well for years
to
come, but there are a few things you
can do to avoid costly maintenance.
1.
Keep the drive well-ventilated . Like a refrigerator,
it
needs a few inches
of
air
circulation on all sides to work properly.
2.
Use only good quality diskettes. Badly-made diskettes could cause increased wear on
the drive's read/write head. If a particular diskette
is
unusually noisy
in
use,
it
is
probably
causing added wear, and should be replaced.
3.
Avoid using programs that
"thump"
the drive
as
they load . Many commercial
programs, and diskettes that are failing, cause the disk drive to make a bumping or
chattering noise as it attempts to read a bad sector.
If
the diskette can
be
copied
to
a fresh
diskette, do so immediately.
If
it
is protected by its maker against copying, the thumping
is
intentional and will have to be endured. Be aware, however, that excessive thumping,
especially when the drive
is
hot, caused some older 1541
's
to go out
of
alignment and led
to costly repairs. Current
1541 's have been redesigned to prevent the problem.
Note: the
"Memory-Write"
example
in
Chapter 8 temporarily turns
off
the bumps.
4.
It
would be a good idea to have your 1541 checked over about once a year
in
normal
use. Several items are likely to need attention: the felt load pad on the read/write head may
be dirty enough to need replacement, the head itself may need a bit
of
cleaning (with
91
%
isopropyl alcohol on a cotton swab), the rails along which the head moves may need
lubrication (with a special Molybdenum lubricant,
NOT oil), and the write protect sensor
may need to be dusted to be sure its optical sensor has a clear view. Since most
of
these
chores require special materials
or
parts,
it
is
best to leave the work
to
an
authorized
Commodore service center.
If
you wish to do the work yourself, ask your dealer to order
the 1541 maintenance guide for you (part number
990445), but
he
aware that home repair
of
the 1541 will void your warranty.
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