PC powered itself off now it won't come back on!!?

[Frichager]

I've been having all kinds of problems since the start of this its driving me nuts. First my hardrive went out, then it turned itself off while playing Age of Conan i guess it overheated, I quit playing the game til my new vid card comes in. I put in a new hardrive and soundcard. Last night was updating all the drivers for the motherboard ect. While I was at work last night my gf said it just turned itself off (yes i forgot to turn it off in a rush to get to work). I tried turning it on and got a flash of light from the LED's and light on the soundcard but then immediatly turned itself back off. I was in the process of eventually upgrading the powersupply and I hooked the new powersupply up and same thing lights flashed and immediatly turned itself back off. While testing the monitor was not plugged into the pc but I'll be trying that soon enough but any other ideas? I'm really hoping i didn't smoke the motherboard overnight.yeah i have an AMD ASUS A8N-SLI premium ... no i wasn't pulling wires while it was on i'm not that stupid.also i don't know if it matters or not yesterday when I turned on the computer i noticed the clock timer was wrong by a few hours.

[Fatt]

If you were plugging in and pulling out cards while the PC was still turned on, that can cause serious problems...but sometimes you can get lucky and get away with it.You need to check all of you cables. if any are plugged in backwards this will sometimes short and prevent the system from turning on.Sounds like power issues. If your cpu fan and temperature is ok, then look for the power supply to be causing problems. The power supply can be the problem and still appear to be working. Some people think that if the computer turns on, then the power supply is ok...but, it may be putting out the wrong amount of DC voltages.Something else to check are the capacitors on the motherboard. These are cylinder shaped electrical components on the motherboard. Make sure that they all have perfectly flat tops and that no pink or grey goo is leaking out. If the tops of any of these are "puffed" out then you need a new Motherboard.

[Bobfelter]

If the computer was previously overheating & you left it on unattended, then it is quite possible that you smoked wither the CPU or the motherboard. The symptoms you describe are consistent with a CPU damaged from overheating.I recommend removing the CPU and inspecting it for signs of overheating. What you look for depends on what processor you have. In general, look for black spots on the bottom of the cpu or bubbled areas on top of the CPU.Then reinstall the CPU. Make sure the heatsink & fan are mounted securely on top of the processor. Then try to boot it again.I have seen many overheated AMD chips that caused the motherboard & CPU to both fry.

[streblo17]

This recently happened to me. It was the motherboard and now works perfect after a replacement was installed.