Secondary Hard Drive acting up
 

By "acting up" I mean that within the past few days, occasionally my secondary hard drive that I keep anything not related to the OS on has been randomly disappearing from my computer. Not physically of course, but it fails to register, and doesn't show up on the Device Manager. After some time or after a restart it will reappear, but I can't figure out what's causing it.

I scanned the disk and it says that there were no errors or bad sectors, so I'm unsure if it's failing or if I'm doing something wrong. The only thing I've done to it this week is defragged it, but I can't see how that would have caused it problems.

Any thoughts or input would be greatly appreciated. Thank you.

I would suggest checking the physical cable connections from your HD to the motherboard. It might be lose or the data cable has become defective. Try using another data cable for the HD in question.

This is an internal hard drive, right? If it's external, I would suspect your enclosure.

I presume you're using Windows. It's been a while since I used it, but are you getting any messages about how a drive was improperly ejected? Do you hear any change in sound when the drive disappears or reappears (is the drive powering down/up)? How old is the drive? How often is this happening? You mentioned that a restart can get it to reappear; do you restart often, and has it happened since restarting?

I'd also echo Wandering_Youth's suggestion about swapping out the cables, if you can. If you don't have a spare cable lying around, you could swap the cables between your primary and secondary hard drives. That should let you know if there's a problem... pretty quickly. The problem is that if it is the cable, when your main drive goes offline you might experience some data corruption. There's a bit of a risk.