I have a huge problem regarding my computer shutting down.
I have Athlon 64 X2 4800+ with 2GB of RAM, GeForce 8600 GTS, and Windows XP installed (SP 2).
Originally I had a no name 500 W PSU intalled in my case.
The first problems I encountered when I purchased Bioshock and started playing it. Shutting downs started to happen after some 1 hour of playtime. It was almost eliminated when I started to play the game in lower res. Nevertheless, the issue escalated when my computer started to shut down on other tasks, like compiling an AVI movie or playing two YouTube movies at the same time. It's possible that I didn't push my PC like that earlier, althought calling that "pushing the PC over its limits" is silly....don't you agree?
Each time the computer shuts down it won't start (shuts down again on Windows starting screen) for about 15 minutes. These 15 minute periods are quite repeatable.
After a while I bought GeForce 8800 GT OC from a friend, and we tried to install it. But each time we got Windows starting screen and the graphics card pulled the power the computer shut down. This lead us to conclusion that the the problem is in the PSU.
Ok then. I go out and buy myself a new PSU, Raptoxx 600 W PSU. A good brand (according to reviews), more than enough power....problem solved....right?
I installed the new PSU and in the same time the better graphics card - GeForce 8800 GT OC. The computer would power up fine and load Windows, but I would get a black screen now (all plugged in properly). The card got fried with the old PSU? Maybe. It's not like I need that card badly. I just wanted to get rid of the shutting down problem. So I pull out the new card and place in the original GeForce 8600 GTS, connect it all, power up my PC, and WTF?!? The computer shuts down. I tried to power it up immediately....again, it shuts down. I wait for 15 minutes...ok...Windows loads fine. I start installing various temperature monitoring programs, and during installation of one....oh no, my PC shuts down again. You can guess I'm furious. Is it possible that a no name 500 W PSU is more stable than Raptoxx 600 W PSU? The shutting down countinued each time my PC was slightly more active....like, when I heard the fan (not sure which fan - CPU or GPU) would work louder for few minutes.
Do I have a problem with my graphics card too, or maybe the old PSU damaged the card so it's causing problems to my new PSU? Is it a motherboard (Gigabyte S-series GA-M52L-S3) problem? I mean...I replaced the PSU...man, do I need a new motherboard now. I can as well buy a new PC then. Sigh.
SpeedFan never reported any temperatures above 70 °C. They are usually around 55.
Temps look fine, however I'd look for a GOOD QUALITY PSU from: Antec, BFG, PC P&C, OCZ, Corsair, Zalman, or even Thermaltake. Secondly what case do you have? I'd suggest a case with better airflow such as an Antec 300.
Just because a psu states that it is 600W dosn't mean that is what it is outputting, 600W may be it's peak (only to be held for short bursts ie bootup). Cheap ripoff artists that make PSU's love to add a few resistors to a 400W and call it a 600. A cheap PSU could also severely damage your MB via voltage spikes/unstable power. The manufacturers I listed above are expensive for a reason THEY ARE ALL GOOD!!!!!!! also they usually also have a waranty for 3+ years (some even longer).
My core temp goes over 70 °C even after I reapplied a new layer of thermal paste. I'm buying a new case with fans today. Yeah, the current doesn't have them...but it never crossed my mind I should get one.