New backup drive won't boot

[Pisces]

Originally Posted by dnanian

Well... if System Preferences thinks it's bootable, and it's a "Backup - all files" made with "Smart Update" or "Erase, then copy", it should be bootable.

Try the "applications won't launch" fix posted at the top of this forum.

Thanks for the suggestion, but my applications launch just fine from the unbootable backup. Everything works like it's supposed to from the backup when it's mounted, but it just will not boot.

Since my original post, I've discovered that now my older external firewire also will not boot even though it too appears in System Preferences as a bootable Startup. I've done successful Smart Updates on this drive for over a year, about half of which I verified as bootable by booting from the external drive in question. Now it behaves just like the new drive (won't boot).

Also tried:

Power + Option key on both drives. 1) New external drive: both internal and external icons displayed with the internal selected (arrow), but the cursor will not move at all to select the external drive or boot from the internal. 2) Older drive: external icon not displayed; booted from internal drive.

Power + Shift key (Safe boot): behaved the same as regular boot on both drives -- Safe boot did not solve the problem on either external drive.

I am now without a bootable clone for the first time since I started using SD three years ago (2.5 years on a Pismo with Panther and Tiger, 7 months on the MacBook with Leopard).

If neither external drive will boot even though both show in System Prefs as bootable, does that mean that something is wrong with the MacBook itself?