How To Fix: Mac Firewire Drives Do Not Mount on OS 10.4.11

Yesterday I booted up the ol’ G4 for an exciting day of scanning 35mm sprocket Holga negatives for an upcoming show. I fired up the external Seagate Firewire backup drive that sits on top of my computer, but the drive didn’t mount. The machine is running OS 10.4.11. Here’s what happened next:

  • Checked the power and Firewire cable — OK — rebooted the machine. That didn’t help.
  • Booted an old laptop that’s running 10.4.5 — the Seagate external drive mounted and worked fine.
  • Powered down the G4 and tried a different Firewire cable. The drive still wouldn’t mount.
  • Unplugged all other peripherals except the keyboard and mouse, rebooted, tried the other Firewire port. Still no go.
  • Next I did some searching on the Internets and found lots of other people had this same problem with OS 10.4.11 and various versions of OS 10.5. Not a lot of fixes were listed, but the first one that I tried worked great. Thanks to Rolf Nordahl who posted the fix.

Here’s the fix that worked, by booting into open firmware:

  1. Power down your machine and completely unplug the power cord. Make sure the power cord is not attached to your computer. Pull it out. Let the machine sit for at least 20 minutes.
  2. Restart the machine while holding down command-option-o-f (that’s “o” as in lmnop, f as in frank)
  3. At the command line type in: reset-nvram [return]
  4. At the command line type in: reset-all [return]

The machine will now boot up. Try plugging in your Firewire drive and booting. If the drive mounts OK that’s excellent. Try rebooting the machine to make sure the drive will mount on a subsequent reboot to make sure.

Both my Seagate backup drive for my G4, and MacGurus Burly hotswappable multidrive backup for my photo archive can use Firewire and USB (Firewire 800, 400, and USB2 on the Burly). Firewire is faster (especially Firewire 800), but I’m glad I’ve got drives that will run on a USB connection for backup.

Update: If you’re running Leopard instead of Tiger and your Firewire drives won’t mount, and you’re on an Intel machine instead of Power PC, you might try a different procedure for zapping the PRAM as outlined here.