Try taking out your CPU and reseating it. I had an AMD machine do that a while back and when I reseated it, it POSTed.
Other suggestion if the CPU thing doesn't work is try one stick of RAM at a time, switching them if it doesn't work the first time.
You can try a different power supply if the above doesn't work. Some motherboards are sensitive to certain power supplies, though generally it won't boot if it is power supply but you never know.
I've done the Ram swap out and the same results, I'll try taking out the CPU, that sucks, i don't want to take it apart, but i will if i have to!