FWIW, a couple years ago I went through a situation similar to what you're
going through. During my Internet research I learned that firmware versions
of controller boards may vary between otherwise identical looking drives,
and this might result in a compatibility problem. The person I learned this
from commented that after he went through swapping controller boards and
discovered the firmware difference, he made it his practice, when buying a
new hard drive, to always buy a second identical drive at the same time from
the same batch as the first (to ensure matching firmware) so he could
confidently swap the controller boards should he need to.

Hope this helps.
Fabian

"Jaz" wrote in message
...
A have a Maxtor 20GB 2B020H1 which is doing the spin-up then spin-down
thing. The controller says ATHENA ATA2-PLUS, FBII 301430100.

I found this site http://www.hddtech.co.uk/MaxtorFailureSymptoms.htm
and my symptoms match precisely. So I bought a working 2B020H1 used.

I swapped the contoller but the drive isn't recognized at POST. I
swapped the controller back to the spare-parts drive and that one
works fine. Worth noting is that with the spare controller, the
original drive no longer spins down after spin up.

Then I noticed that the spare controller part number is slightly
different. The new one reads "ATHEN II/POKER". What's interesting is
why this controller would not be detected by the BIOS when attached to
the old platter assembly. I verified that the geometry and the Maxtor
part numbers are both the same.

Anyway, aside from trying to find another spare controller that
matches exactly, and before I resort to an $800+ professional
recovery, is there anything else I should try?

Thanks.
Jaz
(Please excuse the 'burp' when replying (b))