The data isn't critical, but would be nice to get (music files, mostly).
What I'd really like is to get this drive operational. It was pulled from a friends USB external hard drive, and it has problems when connecting to two of my desktops.

Recognized in BIOS
Recognized by HDAT and HDD Regenerator from Hiren's
Not recognized by mini-XP (Hirens), WinXP or Win7
Not visible in "Disk Management" in either WinXP or Win7
SeaTools Short Test failed with Test Code: A9E1D66A

Scans run by HDAT and HDD Regenerator run extremely slow.

Are logic boards still hard to find? I had the idea of replacing it, on the chance that it is bad. I find no evidence of burning, etc... and the HD doesn't make any unusual noises.

Any suggestions?

Sounds like bad sectors. You need to clone it with professional kit or pay someone to do it. NEVER EVER RUN HDD REGENERATOR OR SPINRITE ON ANY HARD DRIVES! It will cause more damage.

Or else, save your time and get a new drive.

Clone it with ddrescue (freeware).

_________________
A backup a day keeps DR away.

Thanks for the suggestion. I read you on TSF also, lol...
Is there any way to repair the HD? I thought "bad sectors" could be repaired? Ignored?
Is there anything to try?
If I can fix this, I'll get a 750 Gbyte HD for free.

Bad sectors will be reallocated automatically, in due course. Just zero-fill the drive, if the data are of no value. You could use SeaTools for DOS to do this.

_________________
A backup a day keeps DR away.