Raid 0 won't work anymore

In May of 2001 I purchased and set up a Promise fasttrak 100 controller
along with 2 IBM 60gxp 40 gig HD's running raid 0, surpisingly with
heavy usage all has gone well until recently.

I can't boot into windows anymore, when I boot into the promise fast
build utility it tells me one of the drives is off line, I tried
switching the ribbon cables, power supply lines etc but still no luck.

I ran the (latest) IBM DFT 32 ver 408B utility which would lock up
towards the end of the mechanical test in the basic and advanced mode
on both drives so I removed the Fasttrack controller and connected the
hard drives to the MB and ran the basic and advanced test on both HD's
several times and the results were great, both completed all testing
with no errors.

What are your thoughts? Does this mean the Promise controller conked
out, the motherboard may have issues or there may be a problem with one
of the HD's that the test isn't picking up?
also the MB is an ASUS P3B-F

Rick