Quote Originally Posted by napox9 View Post
Today I connected my PSU (Corsair VX550) to my old P4 and got same problems !!!!!11one
I will RMA this PSU later this week, it was much easyer for me to put the blame in the mother-board/ memory/ video card than the new PSU.
I guess the learning of some things come only at the hard way.

I will update you after getting the new PSU.

My Kill-A-Watt reads 528w at the wall with a single 4870@800/1100 and a q9540@3.92 running furmark and prime, but that's with a single 7200rpm HDD and not much else. Bad PSU or not, you're definitely straddling the line at 550w... You may consider upgrading it instead of replacing with the same.

--Matt