I spent most of last night helping out a friend whose Mac had suddenly stopped booting properly and was instead flashing a ‘not allowed’ symbol (no sign, prohibitory sign, denied, circle slash, ghostbusters). Interestingly enough, in working w/ OS X since it came out, I’d never seen it before.
Held down ‘v’ on boot to see what it was hanging on. It couldn’t find the root device. After trying zapping the PRAM and NVRAM to no avail, I booted the rescue disk and checked the drive utility. It couldn’t see the HD. That would explain things. The drive sounded fine, so my suspicion was on the card or cable, but when I swapped drives it worked. But then, booting it again, it didn’t. Swapped SCSI card/cable and put old drive back in and it worked. I can’t really explain it, must be some bizarre connection problem.
- Mac OS X: “Broken folder” icon, prohibitory sign, or kernel panic when computer starts
- Pismo with Panther won’t start up…weird symbol..
- OS X – (/) symbol replacing Apple at boot
- Recovering from a Blinking "?"
- Booting Mac OS X
- Some Useful and Interesting Terminal Commands for Lab Managers
- Magical Macintosh Key Sequences
- Open Firmware Quick Reference