At times, your computer might freeze up altogether—refusing to let you interact with any applications or shut it down. This is known as a system crash.
An occasional system crash can happen, regardless of how well you maintain your system. However, if you encounter crashes several times a day, something is definitely wrong. Your system might be having a conflict with some new software or hardware you've installed, or might be experiencing the initial symptoms of a dying hard drive. Fortunately, there are ways to check for the cause of such problems. Consider the following:
- Recent software installations—What did you do just before your computer began to crash? If you just installed some new software, maybe one of those files is causing a conflict. You'll want to check the program's documentation (or Read Me file, if there is one) to see whether the publisher is aware of any problems.
- Recent hardware upgrades—If you just installed a RAM upgrade on your computer and it is now crashing, maybe the RAM module you installed is defective. It's always possible and not easy to test for. You might want to consider removing the RAM upgrade, strictly as a test. Then work with your Mac to see whether the crashes go away. If they do, contact the dealer for a replacement module. If you've installed an extra drive, scanner, or other device, disconnect it and turn off its software to see whether the problem disappears.
- Hardware defects—As with any electronic product, there's always a slight chance that one or more of the components in your computer might fail. In the vast majority of cases, however, a software conflict (or defective RAM) causes constant crashes. If you've tested everything and your Mac still won't work reliably, don't hesitate to contact Apple Computer or your dealer and arrange for service.
Forcing a Shutdown
If your computer refuses to shut down or restart in the normal fashion, you have to force the process. Forcing shutdown is done in different ways on different models of Mac. On modern machines, pressing and holding down the power button for 6 seconds shuts down the system. After the computer shuts down, turn it on as you normally would.
On some older Macs, you might have to locate a tiny Reset button labeled with a triangle-shaped icon and then press it. On even older models, you might have to use the point of a pencil or a straightened paperclip to press the button. As soon as you press and release the reset button, your Mac should restart normally.
If attempting to reset your Mac fails, your only remaining option is to unplug it, wait 30 seconds, plug in your Mac again, and turn it on. Because it's much more drastic, consider this action only if the process described earlier doesn't work. At this point, you should be able to start normally, except that you might find the startup process pauses for some extra seconds at the Checking Disks prompt on the Mac OS X startup screen. A forced shutdown can cause minor disk directory damage, which is fixed during the startup process. This should not be any cause for concern.