My pc has developed a habit over the last few months of turning itself off without warning.

There's no shutdown screen, just a sudden lack of power to the tower. The monitor also turns itself off although the standby light remains lit. The PC then refuses to start untill I have turned it off at the wall for a few seconds and then the pc starts fine.

It seems to happen more frequently when running graphics intensive programmes, or if the ph has been on for a while which makes me think that the graphics card is overheating although I have no way of checking this.

I'm considering buying a new graphics card but I don't want to fork out for something I might not need, and then still have the same problem.

The graphics card is an Geforce FX 5600. The fan seems to work just fine, and i've done a thorough check for viruses etc. I'm running an AMD Athlon XP 2800+ with windows XP pro.

Any help you can give would be welcomed.

im getting this on my other computer, very recently , i use an AMD athalon graphics, every so often the computer shuts off and i have to use the smaller reset buttun :S then it does some daignostic thing at startup..wierd...