Slave drive acting up...

[Red Machine D]

So I've got a Samsung Spinpoint HD501LJ 500GB SATA HDD. I had it in a SATA-to-USB external enclosure for a while and it was working fine. I removed it from the enclosure and put it back in my tower and mounted it back in the HDD rack with the typical care associated with moving HDDs. Cables in, jumpers, everything. Plug the tower back in, flip the PSU switch, power up, not detected. Not in Win7, not in BIOS, nowhere. The HDD light is blinking rapidly as if it's constantly accessing, and since the slave isn't showing up, I figure it's the problem. I grabbed a stethoscope and listened carefully and yes, it IS alive, but it's not reading or accessing or showing up at all.

Advice? Answers? Can I fix this thing at all? I really hope I can, as it's full of stuff I would like to keep.

 

[Red Machine D]

Ten-hour bump. Hoping I can get help for this; recently found out that this particular HDD has my high school photos on it. I don't have the negatives anymore. ;_;

 

[entropist]

If it's not showing in the BIOS, but is spinning... sounds like a bad data cable (or just incomplete insertion on one end) have you tried replacing/reseating the cable?

 

[sub.mesa]

What jumper did you place? You shouldn't use any jumpers with SATA drives; try to remove it.

Does the HDD spin up? Feel with your hands.

 

[Red Machine D]

Removed jumpers, swapped cables, tried all combinations possible and still nothing.

edit: Tried a brand new cable that came with another HDD and still nothing.

edit2: Took a good look with an LED flashlight and all the contacts are intact. Plugging in and turning on and there's definitely activity going on, just not being read by BIOS...