mac mini won't boot - hardware test error

Very likely to be the hard drive, though it can also reflect a fault in the drive controller which is integrated on the logic board.

Have you had any indication of problems which could have been drive-related, recently?

I'm not a great believer in the accuracy of the hardware test reports, but the fact the system booted at all and that (unless I mistake which system you're referring to) yours is a G4 1.5 mini, it would tend to indicate the drive controller is not at fault - the optical drive being on the same ATA device!

Drives do fail without warning of course, so it may well be that yours has simply done that. Often though there is some symptom of impending doom from a faulty drive, even if just unusually long load times for apps or files, or the occasional hang.

Can you access the drive in Disk utility from your install (or retail) MacOS disk? If so, what does it report when you try and run the repair disk task?

As I say, it's worth seeing if you can prod it and get something meaningful via Disk Utility first - though likely a new drive will be required.

The variable reports on the hard drive are not entirely unusual with a drive that has problems, but it's not a good sign in general that you are having issues with booting to the install disk. That has potential to reflect a controller error that could be minor in nature and even be as simple as a poor connection on the drive carrier which has both drives mounted to it.

Try booting to the OS installer again. If you can get past the language selection screen it means OSX (the very basic version on the installer) has loaded, and that's a good sign. There's no reason from that point that the Utilities menu wouldn't pull down as normal and disk utility run from there. If you can get that far, see if the internal drive is visible on the left of the disk utility app, and if so, select it (there may be two entries for it, either will do) then click the repair disk button.

It won't work in your MBP. That uses a SATA drive and the mini has an IDE - wrong interface. Plus the mini's drive has a PPC MacOS and that wouldn't boot the Intel laptop even if the drive fitted and was fully working!

Ah right! OK, let us know what you find!

Good news that it's all back and running with a new drive, but it's maybe not a surprise that data recovery on the old drive could have been a chore if the drive was failing - drives mess up pretty comprehensively when they mess up at all!

Thanks for letting us know how it turned out!