When you say no POST, does your mother beeps?
If so,beep sequence is error report, actually!

If not, I would suggested that you take out one memory stick and try again,
nForce chips have a very strange taste on memories! There should be nothing
wrong with the memory, but the nForce chip just don't like them ;-)

I had try 3 different made RAM modules before my 2500+ will run stable
200MHz FSB!

Also, try lock you RAM speed at 166MHz and just increas the CPU FSB.