Hi David,
Do you not get the ROM boot screen or anything else? i had one in my 500 with the A590 hard drive (which is almost identical to the 2091 as far as I know). My machine would not boot from HD
Any time I had the RAM enabled on the MTec, but in your case it sounds like maybe the board isnt functional at all.
If you do have a HD boot issue, I was able to sort of work around that issue, and I can tell you how, but I eventually switched to a different HD controller which solved the problem.