Apple did an in-depth report of troubleshooting techniques and
their effectiveness. This is what they found:
- Extensions troubleshooting worked 56% of the times it was
tried.
- Clean installs worked 28% of the time they were tried.
- Disconnecting SCSI devices worked 21% of the time that it was
tried.
These are all valid troubleshooting steps. They have a high
likelihood of resolving your problem. To further clarify:
Extensions troubleshooting is the most widely applicable
troubleshooting step. It is appropriate for any error type 1,
2, 3, 10, 11, 25 or freezing in addition to miscellaneous weird
behavior. If the issue occurs on startup or in multiple
applications, this is the best bet. If you're going to guess
anything, guess this.
Clean install. When all third-party hardware and software
have been eliminated and the issue persists on startup or in
multiple applications. Reinstalling system software may
be appropriate. A clean install is not necessary if a
custom-install or easy install will fix it. If you have
narrowed down the issue to a certain file or the issue seems only
to affect a certain component of the system software, you should be
able to quickly custom-install that item and fix the issue. A
custom-remove is also not, strictly speaking, necessary before a
custom-install. There is a lot of recovery required after a
clean install. Many users do not understand how to recover from a
clean install. It's best avoided unless simpler steps don't fix it.
At times it is appropriate, but other times, it's overkill.
You can save a lot of time here by doing the quickest thing to
resolve issue, not the easiest.
Disconnecting SCSI devices.
This step is appropriate when a computer starts with a only gray
screen and a pointer, but goes no further. Random hard freezes and
recurring directory corruption can also be signs of SCSI chain
problems. Many users do not realize that all SCSI devices
should always be powered on before the computer is started and then
left on at all times while the computer is being used. There are no
exceptions to this rule. This is explicitly stated in every
Apple computer manual put out since 1996. Users often miss this
point and have chronic problems because of it.
In contrast, the following troubleshooting steps are tried way
too often.
- Rebuilding the Desktop worked 0% of the time that it was tried.
It was tried 54% of the time.
- Deleting Preferences worked 3% of the time that it was tried.
It was tried 38% of the time.
- Zapping the PRAM worked 5% of the time that it was tried. It
was tried 77% of the time.
From this we conclude that time spent doing these things is, for
the most part, wasted. In an effort to provide relevant
troubleshooting, please try to limit the use of these steps to the
following situations:
Rebuilding the Desktop should only be tried to resolve
generic file icons (but not the generic Chooser icon in Mac OS
8.1). A single generic icon is often a file level problem (such
as a bundle bit), that rebuilding the desktop won't fix. In
rare cases, application/document connection problems can be fixed
by rebuilding the desktop. (For example, you double-click on a
document and it opens the wrong application. However, Easy Open
does this same thing by design.). This can easily waste several
minutes while troubleshooting, especially on larger drives.
Moving Preferences should only be tried when an issue is
isolated to a specific item (Finder, control panel, application).
Usually, the program will crash on startup or the
application-specific settings fail to "stick" when you quit the
application. It is not necessary to actually delete the
preferences, just move them.
Resetting the PRAM should only be tried in cases where
PRAM-resident settings are not "sticking". These settings include
startup disk, keyboard control panel settings (repeat rate, delay
until repeat), sound level, memory control panel settings (RAM
Disk, Virtual Memory, Disk Cache, 32-bit Addressing), mouse control
panel settings (double-click speed, tracking speed), selected
AppleTalk port, highlight color, default printer, Date & Time
Control Panel (Time Zone, Daylight Savings Time only), General
Controls (Folder Protection, Insert Blink, Menu Bar blink only),
plus undocumented features. Keep in mind that resetting the PRAM
resets all of those settings to their defaults and requires you
to reset any settings you changed. The following control panels
are not affected by zapping PRAM: Energy Saver, File Sharing, Text,
Numbers, Speech, PPP, TCP/IP and many others.
Resetting PRAM can affect ADB and serial port issues and little
else.
Reformatting the hard drive should never even be
attempted unless Disk First Aid reports problems that it cannot
fix. Unless a bad hard drive is suspected, a low-level format
should also never be tried. Zeroing all data should also never
be tried unless you want to prevent data recovery.
