Apple Power Macintosh 7600/200 Series - Manual (Page 181)

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Diagnostic Techniques
This chapter provides detailed instructions on several techniques you will use
to diagnose and fix problems involving system software and hard disks. You
will learn how to check your system extensions, start up from your system
software CD-ROM disc, and test and repair disks. You will also see different
ways to install and remove system software and learn how to use Apple
System Profiler, a utility that allows you to quickly view different types of
information about your computer.
Checking your system extensions
System extensions are files that add features to your system software. Some
extensions are incompatible with one another, with certain programs, or with
Macintosh computers built with the PowerPC microprocessor. To check
whether an extension is causing problems, follow these steps:
1 Start up your computer while holding down the Shift key. Keep it held down until you see
the message “Extensions off” in the Welcome to Macintosh box.
This procedure turns off all extensions.
If your computer starts up and runs normally, continue with this section. If it
doesn’t, turn to the next section, “Testing and Repairing Your Hard Disk.”
Consult this chapter to learn how to
check system extensions, test and repair hard
disks, install and remove system software,
and use other diagnostic techniques.