My computer shuts itself off

[aclarke]

My computer has just started shutting itself off after maybe 0-10 minutes of use. Sometimes it shuts off before I've even logged in, and other times I can use it maybe 10 minutes or so. I then hold down the power button for a few seconds like I would to force a powerdown if it was up, then press it again and it restarts. It's been maybe 1.5 weeks since I last added any hardware (SB audigy x-gamer) so I don't think it's that. Any ideas? I work on this computer so I need it to be up!

- MSI K7T266 Pro2-RU motherboard
- AMD Thunderbird 1400
- 768MB PC133 RAM
- Windows XP Pro
- SB Audigy Gamer
- 2x40GB RAID-0 plus another 40GB hd
- inno3d GeForce 2Ti card (agp) and older Creative Labs video card (pci)
- DVD-ROM drive, CDRW drive, floppy drive
- SMC NIC

 

[SWScorch]

Could be heat. Make sure all your fans are running, and clean out any dust that might have settled in there (especially in the heatsink.) Just yesterday, I went over to a friend's house to fix her comp, and it rurned out two of her fans had stopped working, including the power supply fan, and after an hour the CPU hit 75 C. She had the same symptoms as you. Of course, if you say "0-10" minutes, then thats a short amount of time for heat to build up. But its still worth a shot.

 

[psteng19]

If it's not the power supply, it's the motherboard.
But I'm leaning towards the power supply.

 

[aclarke]

Hey. Well I'm pretty sure it's not heat as it will happen even when it's cooler at night and I've just turned the PC on, and sometimes it can run for hours through the heat of the day (in the 80s or 90s in my room).

I pulled out my power supply yesterday and it smelled burned so I went out and got an Antec TruePower 480 yesterday. I just plugged it in and it made a horrible loud shorting sound and then filled my room with the smell of burned electronics. At least my other power supply works sometimes!

I'm concerned that I may have a short elsewhere in my computer that caused this, or that my new burning power supply has caused damage elsewhere in my computer. Is it likely that I just purchased a bad power supply or is it possible that a short somewhere else could have caused this?

 

[aclarke]

So I put in a new Antec TruePower 480 power supply and MSI KT3 Ultra-ARU motherboard into a new case, along with my old hardware. It started to boot up, and then I noticed smoke coming off one of my hard disks (from the looks of it). I quickly powered down, and noticed that I hadn't plugged my power supply into any of my drives. I plugged it all back in, and now all that happens is the lights all come on and the fans start turning for maybe 1/10th of a second, then it stops.

Help, what's wrong?!