I have a 3-year-old Intel Mac Mini at home. About a month ago, it stopped booting from the hard drive (internal, SATA, 80GB). I tried booting from the Install Disc to repair the filesystem but Disk Utility was unable to do so ("invalid node structure"). I was also unable to use the hard drive in the Terminal from the Install Disc nor from an Ubuntu boot CD ("DRDY err"). I could see the contents of some directories, but others would give an error and I would get failures when trying to copy files. At this point I was sure the filesystem was hosed and I'd want to reformat at least.

DiskWarrior was able to let me retrieve the data files I was interested in, which are now copied to an external hard drive, but it reported a high number of problems ("speed reduced by disk malfunction" count was over 2000) when in the process of trying to rebuild the directory for the drive. It also would not let me use the rebuilt directory to replace the one on the drive; it claimed the disk errors prevented recovery in this way.

Under normal circumstances I would now assume that the drive itself was going bad: DiskWarrior's "disk malfunction" error above is supposed to imply hardware problems. My initial plan was to buy a replacement for the internal 2.5" drive. However: Disk Utility, command-line tools and DiskWarrior had reported all along that the SMART status of the drive was okay/Verified. So I'm now worried that the drive hardware is actually fine, and that the problems were due to a disk controller that has gone "bad" somehow. If this is the case, I'll probably just replace the whole computer.

Any advice on how I can tell what is to blame? I don't have a lot of extra hardware sitting around, so I don't have the option of simply dropping the drive in another machine or popping another hard drive inside the Mini.