More likey it isn't the CPU. It could be the PSU and yes you tesed it but it could be over heating too to a point that it shut down.
The chance that both video doing the same. I would try another PSU if you can some body to give one to try.
The reason I didn't think it was the PSU was because I'd tried another one already. Granted it was only 400W, but should be able to handle it.
I just booted without the video cards installed and it still shut off, so it definitely isn't the video card. And again, I've tried other PSUs. I might have one more *old* one to try, but we'll have to wait and see. I'll hack apart that desktop later today.
The CPU seems to be the last remaining thing I haven't been able to test.
Matt
