HDD spins up, but BIOS doesn't see it

The title says it all: the hard drive will spin up normally, but no computer has been able to recognize it. Things I've tried:
-Checking cable connections
-Using a different SATA cable
-Using a different power cable
-Plugging into a different SATA jack
-Using a SATA to USB adapter to plug it into a Mac, then tried it with a PC

So far, nothing. The USB attempts didn't even register as being plugged in. No error message, no request to format, no icon on a desktop or My Computer. Nada.

Pretty bleak, right? I'm looking for ideas on what to do next. I'm going to try booting the original desktop with the drive plugged into a USB port, but I don't have much hope for that.

I figure someone out there has seen something like this before, so if you have any experience with a similar problem please let me know. I'm willing to admit that it's bricked, but I want to exhaust all possibilities before I reach that point.

(Also, this occurred after a hard restart. Can anyone explain to me why that might have fried the disk so thoroughly?)

Yeah, I have seen something like this quite a few times.
The drive is simply dead, it happens.
If it is an older drive and out of warranty, oh well. New drive. $$
If it is a fairly new drive, RMA it.
However, drives don't cost much. To me, it is simply not worth hassle to mess with it as long as you have (unless something really important is on it) or even fuss with the RMA process. I would just go buy a new one and forget about it.