Remember that 750 GB drive that was dead so I opened it up to see what happened? Well, I thought it would be a good idea to tighten that loose screw and close up the drive casing and see if it would still work or not. It is only an external drive, what’s the worst that could happen?
So I turned on the drive, and after a few seconds, it showed up in the Finder! I decided to use Disk Utility to Verify Disk to see what errors it would find. Halfway through, I got the Disk Ejected error, and the disk disappeared from the Finder. It’s a goner.
Then, apparently I didn’t turn off Time Machine, so the OS was trying to write to the disk, but the disk is broken, and that messed up the Finder, and left me unable to reboot. What you see in the image is my screen after trying to restart the machine. It just hung there. So I did a hard reset, turned off the bad drive, and then I was able to turn on the computer and it started up normally.
Do not bother with trying to reuse bad drives, no good can come from it!