Apple 8600 appendix Diagnostic Techniques, Checking your system extensions

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.

11 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:

1Start 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.”

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