PSU overheating or what do you make of this?

This morning I turn on the comp., starts winamp and IE and starts surfing these very forums. After ~30 mins the computer just dies like if I had unplugged the powercord. I stare at the blank screen for a minute wondering what the hell happened. I press the powerbutton. Nothing happens. I unplug the power, put it back in, and it starts up just fine. Scandisk runs. Then after 20 mins it dies on me again. Same procedure with the unplugging and all that.

This time i notice that the PSU´s fan isn´t spinning, and the PSu is quite hot.
Now this computer hasent beeen giving me any trouble whatsoever for the last three months until this.

A week ago I changed my vid-card from a leadtek GF2 MX to a Gainward GF2 Pro but if that was the problem I should have noticed it earlier i think.

I know it isn´t the CPU overheating, the temps are 45 degrees C / 113 degrees F at its worst.

Is this the simply the PSU overheating that is causing this?
I´d be really glad for some quick advice here, I´m about to sell this machine any day now and this just won´t do...

The PSU is a JNC 300 W. It has a sticker on the side where the observant can read the words: Better quality with temperature-controllded fan.

Also, can these crashes damage any of the hardware? This machine is my only means to read these forums...

Any and all input greatly appreciated!

Abit KT7A
duron 750
128 MB Mosel Vitelic PC133
Gainward GF2 Pro
SB PCI 128
Seagate U5 40 GB

Win 98 SE, Via 4.31, 10.80 detonators

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.your signature is wasting perfectly good bandwidth.

I'd suspect the psu also, if it were mine I'd change it ASP, I've seen psu's take out mobos when they die.


Next time you wave - use all your fingers

Yes change the power supply.
As everyone has said it is not worth running the risk of damaging other components.
I don't trust switching power supplies for the simple reason once one of the regulators gets damaged from exessive heat their voltage control can go awry and burn out the motherboard.

<font color=green>I miss the smell of leaded gasoline!</font color=green>