Computer has been shutting down suddenly lately.

[Tim]

I've got a home built system with Windows XP and an assortment of antivirus and spyware programs. AMD Athlon XP 2500+ unlocked week 31, 512 MB PC3200, Abit NF-7.

Lately (about once every 4-5 days for the last 2 weeks), the computer will just shut down on me. It has happened when I was doing something, and it has happened when the computer was idle.

The monitor will go dark and the monitor light will change from green to orange. The computer will still be running and the hard drive light will be on.

Pressing the reset button on the case fixes it and restarts the computer, but I've never had this problem before.

Ideas? Maybe the video card? Mine is a Powercolor ATI Radeon 9200SE.

[primesuspect]

One thing that's missing from that list is the power supply. What brand?

[KingFish]

Random reboots tend to be due to power supplies crapping out, your cpu overheating, or memory issues. What type of PSU do you have, what are your temps, and what brand of ram are you using? Are you using stock memory timings?

[Tim]

The tower case is a Powmax I got from a computer show for $30 new, and the power supply is the 400 watt unit that came with it. It was new, now it's 8 months old. I assume it's a generic power supply unit. Never had a problem until now.

Memory is 2 X 256 sticks of Samsung PC3200, slots 1 and 2 on the NF-7.

Memory timings are stock, system is not over clocked. 11 X 166, 1830 Mhz speed on the processor (also stock).

Right now the case temperature is 28 C and processor is 45 C. Under load (playing one of my videos) it'll go to about 30 C and 50-51 C. It has a generic all aluminum heat sink and fan on the processor. And a thin layer of thermal paste.

I recently removed one of the block off plates for a 3.5" floppy drive bay that is on the front of the case. Air flow through the case increased significantly, case fan rpms dropped 100-200 (presumably due to greater air flow / air load), and case temp dropped about 1 degree C. Processor temp didn't change.

[primesuspect]

I would highly suspect that power supply.

[KingFish]

Ditto on the power supply-would definitely be my first choice. For good measure also consider getting a good quality copper heatsink.

[Tim]

Okay, I'll put that on my list of things to buy.

I should also mention that lately the computer sometimes hangs up. Normally when I'm going through folders or web pages, sometimes it'll pause for a moment and access the hard drives (light comes on), but in the last week or 2 that access delay time has grown from 2-3 seconds to more like 10.

[Buster]

I had a similar problem before and it was a loose screw on the motherboard. The screw barely moved but the computer hasn't reset since. Not sure if that can be it but its worth a try.

[Access_Denied]

yea powmax psu's are genarally the crap of the crap.. a 500w powmax is not even up with a 150w antec.. speaking of antec theres a few on http://www.xoxide.com now thats pretty cheap

[Squill]

Yeah I had the same exact thing happen to me the other day at my friends house, I started up my comp loaded up Everquest 2 and was playing and the computer just shutdown. Lights were still on but my monitor light went out and everything sounded like it was running, I looked at the back on my powersupply and the fan wasnt turning and was making a nasty burning smell. So I shut that baby down and had to throw in a cheap 300watt I had laying around (which I plan on replacing tomorrow). But yeah Powersupply is probably your main problem. Hope that helps. Here's a nice power supply for a decent price.
http://www.newegg.com/app/viewproductdesc.asp?description=17-153-008&DEPA=0

I'm not sure how good Thermaltake's powersupplies are but I know they are a good company so I thought I'd try this one out. $55 for a 480watt. Not a bad deal if you ask me. Best buy and Circuit city are trying to sell 400watts for like $80+.