My computer has recently been shutting its self off, when burning dvd's, wich it's never done before. and I'm pretty sure its not a power issue, as it shuts off, and doesn't reboot. Trying to find a way to monitor heat, I found a prgram called "SpeedFan", it says the cpu is about 40-45c just surfing the web. and the graphics card is about 48-51c. with the case open both temps drop a bit to 36-40c and 47-50c. I can tell just from looking that theres a big dust bunny colony living the heatsink, not sucking that out, will that help a signifigant amount? I've been just using a small house fan as a ghetto solution while burning DVD's. but would these heats warrant buying a case fan (and unfortunatley a new PSU as mine close to its limit)?

You could maybe lower the temps a little with another fan or two, but those temps should not be the cause of a shutdown. In my experience, the most likely cause for random shutdowns is having a PSU that is not powerful enough. How many watts is it?

400watts with 1 12volt rail.

comp:
amd sepron 3100+
GeForce 7600gs (manual said a 400watt PSU was the minimum for a pc using the card, and most the reviews I read people said they all used 350watt PSU's with this card)
1x DVD drive
1x Creative Audiogy card

It's definitely not heat at those levels. the chips should be fine well into the high 60s (and likely beyond; my old machine ran happily at around 75C)

However, if it runs fine with the case off then it could be a heat issue somewhere that the SpeedFan app isn't able to monitor. Definitely dust out those heat syncs; that's a very important part of any computer maintenance regimen (dust is a really good insulator and makes things very hot).

If you just went for "the cheapest 400W PSU" you could find that may be the problem. A good PSU is one of the most important parts of your machine; the cheaper ones are often rated for a certain wattage but can perform well below that or just not offer that wattage reliably.

A power problem wouldn't result in you being unable to turn it on after it shuts down. If that is indeed the case, then it could be heat. However, if the machine turns back on instantly with no problem, i'd blame power (especially if you went for the cheapest offering)

-me

Here is a question to go along with his (seeing as I'm soon going to be coming to the 3 month mark for my new system, time to start cleaning her out, unlike the last box I was using)


What is the best way to clean your system? I'm not really expecting much in my case, as I have cleanable filters on it which I wipe off every week or two, but I'm still sure some gets in there.

OK, I'll assume its the power then. As yes I can restart it right after it shuts off, but it doesn't restart on its own, it just shuts off completely.

what are typically good brands to go with, I'm planning on a 500watt 2x12v? I usually by my pc equipment off newegg.com? are there better sites?

newegg.com is the best site I've found. I've used TigerDirect at times, but I like the Egg better.

You should put on the "delicates" head on your vacuum, and vacuum out all dust from your machine once a month or so. If there are visible dust bunnies, those are preventing cooling, for sure. Make sure the machine is turned off before you do it, though :-)

You fix your problem yet? I'd say buy a 500W just to be safe and make sure which ever one you buy has plenty of good user ratings on Newegg. Either a vacuum or canned air work well for cleaning.

it seem that the CPU&GPU temps are both ok.
can it be software problem,400watt power is usually enough,you know

For reference, older architecture AMD chips were actually known for running very hot. My desktop's CPU, an Athlon XP 3200+ tends to run around 62-68c under normal usage (low to high range). It sounds to me like you are having a software problem. Have you perhaps installed anything new or updated anything recently? Sometimes, the smallest thing can cause serious problems.