Apple Macintosh PowerBook 1400 - Manual (Page 115)

This chapter provides a step-by-step approach to diagnosing and solving
problems involving system software and hard disks. Try the steps listed in
each section in the order they are given until your problems are fixed.
Checking your system software extensions
System software extensions are files that add features to your system software.
Some extensions are incompatible with one another or with certain programs.
To check whether an extension is causing problems, follow these steps:
1 Start up the Macintosh PowerBook while holding down the Shift key. Keep it held down
until you see the message “Extensions Disabled” during startup.
This procedure turns off extensions.
If this procedure solves your problem, then continue with this section. If not,
then turn to the next section, “Testing Your Hard Disk.”
2 Reset the parameter RAM (PRAM) and nonvolatile video RAM (NVRAM) by following the
steps below.
When you reset the PRAM and NVRAM, the settings on most of your
computer’s control panels revert to their defaults (original, standard settings).
You may want to check the settings in your control panels for memory,
networking, and monitors, and any aspect of your work that seems affected
after you reset the PRAM and NVRAM.
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7
Diagnostic Techniques
Consult this chapter before you
call the Apple Assistance Center
to solve problems with system
software and your hard disk.