Mac OS X Leopard: The Missing Manual

Startup Problems

Not every problem you encounter is related to running applications. Sometimes trouble strikes before you even get that far. The following are examples.

Kernel Panic

When you see the cheerful, multilingual dialog box shown in Figure B-2, you've got yourself akernel panic—a Unix nervous breakdown.

(In such situations, user panic might be the more applicable term, but that's programmers for you.)

If you experience a kernel panic, it's almost always the result of a hardwareglitch— most often a bad memory (RAM) board, but possibly an accelerator card, graphics card, SCSI gadget, or USB hub that Mac OS X doesn't like. A poorly seated AirPort card can bring on a kernel panic, too, and so can a bad USB or FireWire cable.

If simply restarting the machine doesn't help, detach every shred of gear that didn't come from Apple. Restore these components to the Mac one at a time until you find out which one was causing Mac OS X's bad hair day. If you're able to pinpoint the culprit, seek its manufacturer (or its Web site) on a quest for updated drivers, or at least try to find out for sure whether the add-on is compatible with Mac OS X.

Tip

This advice goes for your Macintosh itself. Apple periodically updates the Mac's own"drivers" in the form of a firmware update. You download these updates from the Support area of Apple's Web site (if indeed Mac OS X's own Software Update mechanism doesn't alert you to their existence).

There's one other cause for kernel panics, by the way, and that's ...