Yesterday when I was at a site troubleshooting an iMac, whose boot screen kept flashing between a question mark and a System Folder (often an indicator of a failing hard drive or a corrupted system file), I tried and tried and could not get the thing to boot using any of the standard tricks (including zapping the PRAM and resetting the OpenFirmware settings). It wouldn't even boot from a CD or from the MacBook Pro while hooked up via a FireWire cable. I ended up getting the iMac to start up in FireWire target disk mode (holding T when the iMac started up) and this was the only thing that worked—and it enabled me to mount the iMac's hard drive on the MacBook Pro's desktop. I immediately saw the problem: the iMac's HD had been renamed to a backslash character, which must have made the iMac unable to locate the drive during the boot process. I renamed it to "Macintosh HD" and restarted the iMac, and lo and behold, the iMac booted flawlessly, without hesitation. If I didn't have the MacBook Pro and a FireWire cable, that iMac probably would have been thrown out under the assumption that it just didn't work anymore.
Lessons to learn from this experience:
- Mac OS 9 and earlier can't boot if you rename the hard drive to "\".
- There doesn't seem to be a freeware extension to prevent the accidental (or intentional) renaming of the hard drive in Mac OS 9 or earlier. (If you, dear reader, know of some way to do this, by all means please post in the Comments section!)
- Having a Mac laptop is indeed an awesome tool when fixing Macs. If your boss raises an eyebrow when you ask for a Mac laptop, you can refer him or her to this article. If you need more firepower, try this page—gets 'em every time. Or, at least, it did in my case; your mileage may vary. If all that doesn't work and you're forced to use a non-Mac, at the very least you can strut around in your "SMUG VIRUS FREE MAC USER" shirt to show everyone which computer you'd rather be using.