difficult problem

so here is my problem.

pc shuts off with no warning and appearantly no cause..

i can surf the net and not play games for days with no problem, i can run prime95 for 12 hours and no problem..

i can load cs:s and let is sit for hours and no problem..
join a team and boom, shuts off..

can load world of warcraft and it shuts off after about 5 secs..

i can stress test video card for 12 hours straight and no problem..

so far i know its not heat, prime95 stresses cpu and raises temps but its fine..

stressed video card, raised temps and max its capabilities and it was fine, so its not the card itself..

ram tests fine, cpu tests fine...

dont know how to stress test a power supply, if someone can point me to that i can possibly rule that out..

antec 900 case with 4 120mm fans and a 230mm on top running highest speeds

core 2 duo e8400 stock 3ghz
thermaltake spinq @ max speed
evga gtx 260 ssc
4gb g.skill ddr2 800 PI @ 4-4-4-12
asus p5n72t-premium

ideas? give me everything you can think of and if i havent already ruled it out, i will test it.

 

The only way to stress test a PSU is to put a big load on it. BUT that would not be a wise move as a stressed PSU can fail catastrophically, and take out everything connected to it.

I use a FrozenCPU Ultimate PSU Tester for power supply (PSU) testing when I am away from home. It is not as good as a qualified technician testing the PSU under "true" (realistic) loads with an oscilloscope or power analyzer, but they are better than nothing. Just remember these testers can NEVER be used to prove or certify a PSU is good. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you can better detect a "failing" PSU, or one barely within specified tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, not a true load. Alternatively, you can swap out the PSU with a known good one that meets the computer's power requirements.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This then requires poking (with some considerable force) two, hard and sharp, highly conductive, meter probes into the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it.

How did you test your RAM? While programs like Windows Memory Diagnostic and MemTest86+ are good, RAM can still pass tests, and still not play well with your motherboard or other RAM modules. I would try one stick at a time.

Inspect the motherboard for bulging or leaking electrolytic capacitors. These failed or failing capacitors are a common cause of sudden, but seemingly random system lock ups and reboots. The capacitors look like tall soda cans, many of which surround the CPU socket.

All older motherboards, and many of today's less expensive motherboards use electrolytic capacitors containing a liquid electrolyte. Failing (including flawed and/or abused/over-heated) capacitors literally bulge at the seams due to excessive internal pressures. Extreme (and very rare) cases result in a firecracker type explosion that can really stink up a room. Typically, electrolyte just oozes from the pressure relief point, which appears as a symbol or letter stamped in the top of the capacitor casing. The electrolyte can be caustic to motherboards and flesh. Look for white to dark-brown, dried liquid or foam on the tops or bottoms of the capacitors. Bulging capacitors are a sign leakage is about to occur.

A motherboard with bulging or leaky capacitors can be repaired, but often it is more cost effective in the long run to replace the motherboard.

Be sure to first power down, unplug the computer, and keep yourself discharged by touching the bare metal of the case before reaching in.