Per VanguardLH:
There are drives that actually have a USB interface on them? Haven't
seen or heard of one. I have seen and used USB-attached hard disks but
they have a SATA interface to connects to a USB-to-SATA protocol
converter PCB inside the external drive case. The bad USB controller
would only fry the USB-2-SATA converter inside the external case. Did
you remove the hard disk from the USB enclosure and try a new USB
enclosure?

My Bad: I use USB enclosures.

Now that I think of it, though, the drives within the enclosure at that
time were whatever the precursor to SATA was (EIDE?).... dunno if that
makes any diff....

I did try the drives in another enclosure and they did not work. So I
probably was wrong about the source of the problem and it was the
enclosure rather than the mobo. This was a looooong time ago....

But the basic lesson seems to remain valid: keep a couple of backups out
of reach in the heat of the moment and/or stupidity....
--
Pete Cresswell