Hardware or Firmware? I'm not entirely sure...

[ilikenwf]

I have a Seagate 500gb Barracuda 7200.10 ...

To be specific, it's the ST3500630AS.

The drive is 3 years old and up until about a month ago was working fine. It doesn't really make any clicking noises out of the ordinary, although it does make a certain click that it didn't used to in my memory...

I'm thinking head crash, personally...though I was able to pull all but 4 of my files off of it, ~350gb recovered.

The symptom is that while plugged in, it will inexplicably and randomly disappear from the bios/os, regardless of whether it's mounted or not. I use Linux, and so I know it's not some OS error. It worked fine up until now, so I know it's not the bios. I have tried it on multiple machines as well.

I've tried testing with SMART and it has plenty of errors...I'll post the pastebin of that below:
http://pastebin.com/3TzTCtL0

That said, you think it's worth pursuing repair? I've gotten 2x 1TB drives since then...but I really want to figure out what went wrong.

[HWHacker]

It would seem that to disappear from bios/os i would have to go not ready. It is a little hard to say without further testing but I would suspect a PCB problem. These drives have a serial diagnostics port. Withthe correct adapter you may be able to learn something about what is happening.

[granaryloaf]

It is worth pursuing a repair if that is what you want to do for the purpose of learning a bit about your HDD.

It is not worth pursuing a repair if there is a warranty on the drive that you can claim under. It is certainly not worth the time and energy if you just want your drive to be usable again. There is a reason it failed and even if that reason can be resolved, often it is down to a problem that will reoccur.

[hddguy]

That said, you think it's worth pursuing repair?

No. You are fortunate to have your data so just be happy and throw this in the trash.

[coffeebean]

Smart errors, drive goes offline, ID's in BIOS on start-up.

Almost 99% dead certain it is not pcb.

Almost dead certain start of media failure.

do what hddguy wrote.

[bhandarigroup]

I think you ave to be a new one. It's already gone and It is worth pursuing a repair if that is what you want to do for the purpose of learning a bit about your HDD.