Not sure exactly what “a bit kerplunked” is, but I like it and I get the idea.
Recommend a little gem of a utility:
Active@ KillDisk .
I’ve been able to resurrect a few kerpluncked hdds that windows just couldn’t seem to get up and running smoothly using this app.
The freeware version (this is what I’ve used) basically is a watered-down version of the US DoD’s utility for data destruction. The freeware version will do a 1-pass overwrite with all 0’s.
Like I said, it’s free and it’s also easy to use. Be absolutely certain you have selected the correct hdd. You’ll receive several prompts and eventually have to type ERASE-ALL-DATA I usually disconnect the other drives anyway. The method I used was to make a MS-DOS boot disc and then a KILLDISK floppy, which obviously, is DOS program. Best to read the guide.
Simple and very effective.
If this fails, I’d do as CDan suggested and toss it.