I went through these questions but they all seem to be relating to new installations of Mobo and CPU. How can I tell on a system I've been running for some time? I have an Asus A8N-sLi Deluxe board and an AMD FX-53 processor. For awhile I was having startup issues - having to hit the power button several times before it actually ran. Then one day, playing BF2142, it just shut itself off. I didn't have another PSU to check with so I ordered a new one, installed it and everything came on, for about 30-40 minutes and then it just shut down, just like it did before replacing power supply. I did have another computer handy that didn't have a power supply so I installed the old one into it and that's what I'm using right now. So, that old power supply wasn't the problem. If I turn the other computer on, with new power supply in it, after sitting for a couple of days it will run, then shut down when it gets warmed up. I don't have the funds to replace both the motherboard and processor so would like to have an idea of which one it most likely is. Rest of specs: 4x512 PNY ram, 1 PhysX GPU - before nVidia... 2xGTX7900oc in sLi config. 4 WD 320GB SATA drives. Ram worked in this computer, so I put it back.

I think you should try to clean it first to see if the problem is just being caused by over heat because of too much dust accumulated by the board or the Cpu's fan. Want A Weekly Update on Latest System Security Problem http://www.systemsecurityinstitute.org

Where's the info about the old & new PSUs? Considering your configuration, you need a damn good one with lots of amperage on the +12v rail...preferably a unit with a single +12v rail with high amperage rather than one with multiple +12v rails of 18-20A each. And you should have paid at least $75 for something decent. Post the CPU & system temps.

Thanks for comments. lycan20, board and everything are nearly spotless. Plus, I have 2 80mm fans and a 120mm fan. Jam, The old PSU is a BFG 650w sLi certified, and it's working fine, it's in the computer I'm using right now. The new PSU is a Coolmax 700w sLi certified. Both were over $75. I don't know, and have no way now of checking, the temps. I'll keep tinkerin', see what happens.