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14 Troubleshooting: what to do (before posting) when things go wrong (Introductory Macintosh FAQ)


This article is from the Introductory Macintosh FAQ, by Elliotte Rusty Harold elharo@shock.njit.edu with numerous contributions by others.

14 Troubleshooting: what to do (before posting) when things go wrong (Introductory Macintosh FAQ)

While the various FAQ lists cover a lot of specific problems, there
are far more problems that aren't covered here. These are a few basic
techniques you should follow before asking for help. You should
probably also perform the ten-step preventive maintenance routine
described in section four, especially rebuilding the desktop (4.3)
and zapping the PRAM (4.4). Following these steps may or may
not solve your problem, but it will at least make it easier for
others to recommend solutions to you.


"Microsoft Word is crashing" doesn't say much. What were you
doing when it crashed? Can you repeat the actions that lead to
the crash? The more information you provide about the actions
preceding the crash the more likely it is someone can help you.
The more precisely you've identified the problem and the actions
preceding it, the easier it will be to tell if the following steps
fix the problem. For example, "Sometimes QuarkXPress 3.0 crashes
with a coprocessor not installed error." is not nearly as helpful
as "QuarkXPress 3.0 crashes when I link two text boxes on a master
page when copies of those text boxes already contain text." The
former diagnosis leaves you wondering whether the bug remains after
a given step. The latter lets you go right to the problem and see
if it's still there or not.


Many companies include a list of known incompatibilities
and bugs in their READ ME files. Often these aren't documented
in the manual. Read any READ ME files to see if any of the
problems sound familiar.


Run Disinfectant or another anti-viral across your disk.
Virus infections are rarer than most people think, but they do
occur and they do cause all sorts of weird problems when they do.



For half a dozen reasons (external magnetic fields, improperly written
software, the alignment of the planets) a file on a disk may not
contain the data it's supposed to contain. This can cause all types
of unexplained, unusual behavior. Restoring from original master
disks will usually fix this. Check to see if the application has a
preferences file in the Preferences folder in the system folder and
if so trash it. This is often overlooked when reinstalling. Since
the preferences file is often the most easily corrupted file in an
application, reinstalling it alone may be sufficient to fix the


Bits are even more likely to get twiddled in the system file
than in the application, and the effects can be just as disastrous.
See question 4.6 for a detailed procedure for performing a clean

If the problem continues to occur after you've taken these
steps, chances are you've found either a conflict between your
application and some other software or a genuine bug in the
program. So it's time to


You need to find the minimal system on which the problem
will assert itself. Here are the basic steps of isolating the
cause of a system or application crash:

1. Run only one application at a time. Occasionally applications
conflict with each other. If the problem does not manifest
itself without other applications running simultaneously,
begin launching other applications until you find the one that
causes the crash.

2. If you're running System 6, turn off MultiFinder. If you're
running System 7, allot as much memory to the application as you
can afford. Sometimes programs just need more memory, especially
when performing complicated operations.

3. If you're running System 7, turn off virtual memory and 32-bit
addressing in the Memory Control Panel. There's still an awful
lot of 32-bit and VM hostile software out there including some
from companies that really have no excuse. (Can you say Microsoft
Word 5.1, boys and girls? I knew you could.) Some of this
software only expresses its incompatibilities when certain
uncommon actions are taken. PowerMacs always run in 32-bit mode.
Try turning the modern memory manager off instead.

4. If you have a 68040 Mac, turn the cache off. Many older
programs don't work well with the built-in cache of the 68040.

5. If you have a PowerPC turn off the modern memory manager.
Some software doesn't get along with it.

6. Restart your Mac and hold down the shift key (or boot from a virgin
system floppy if you're using System 6). If the problem disappears
you likely have an extension conflict. You need to progressively remove
extensions until the problem vanishes. System 7.5's Extensions
Manager lets you decide at startup which extensions to load so you
don't have to spend a lot of time moving files into and out of the
System Folder. In earlier systems you can use Ricardo Batista's
freeware Extensions Manager 2.0.1 on which System 7.5's Extensions
manager is built. See


Use a little common sense when choosing the first extensions to
remove. If the problem occurs when you try to open a file, remove
any extensions that mess with the Standard File Open procedure such as
Super Boomerang first. If the problem remains after the obvious
candidates have been eliminated, either remove the remaining
extensions one at a time; or, if you have a lot of them, perform a
binary search by removing half of the extensions at a time. Once
the problem disappears add half of the most recently removed set
back. Continue until you've narrowed the conflict down to one
extension. When you think you've found the offending extension
restart with only that extension enabled just to make sure that it
and it alone is indeed causing the problem. Although performing
this procedure manually can be fairly quick if you have a pretty
good idea of which extensions to check, it can take quite some
time when you really don't have any strong suspects for a
conflict. In that case consider using Conflict Catcher to help
isolate the offending init. A fully functional timed demo can be
had from


7. Remove all but the required fonts (Chicago, Monaco) from your
Fonts folder. If the problem disappears then one of your fonts
is corrupted. Open the Fonts folder in your System folder and
open each font suitcase until your Mac crashes. The last suitcase
opened is probably corrupt. Restart the machine, remove the
allegedly corrupt suitcase from the Fonts folder and check the
remaining fonts. (There may be more than one corrupt font.) This
procedure may not always isolate the corrupted font, so if no
corrupted fonts are found or if the symptoms do not disappear, you
can use the binary elimination procedure described above to find
the corrupt font.

8. Remove all external SCSI devices. If the problem disappears,
add them back one at a time until the problem reappears. Once
you've isolated the SCSI device causing the problem check its
termination and try moving it to a different position in the
SCSI chain. It's also possible a SCSI cable's gone bad, so
try replacing just the cable.

9. Turn the Mac off and unplug all cables: power, ADB, modem,
printer, network, SCSI and anything else you've plugged in to the
back of your Mac. Then plug everything back in and try again.
Loose cables can imitate malfunctions in almost any hardware or
software. I recently spent a day in panic because I thought my
analog board had died before I could back up the latest draft of
the hardware FAQ. I even went so far as to email my favorite
repair shop (Tekserve, 212-929-3645) before I thought calmly for
a few minutes, unplugged all my cables, and plugged them back in.
My Mac booted up immediately. The power cable had been loosened
when I moved my desk the previous weekend and a few days later
random motion finally disconnected it enough to cut my power. To
all appearances this was an expensive analog board or power supply
failure rather than a cheap cable problem that I could fix in about
a minute at home.


By now you should have a very good idea of when, where, and why
the conflict occurs. If a tech support number is available for the
software, call it. If you're lucky the company will have a work
around or fix available. If not, perhaps they'll at least add the
bug to their database of problems to be fixed in the next release.


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