Random restarts

[j00ni]

my flatmates computer is restarting at seemingly random intervals. It seems to happen most when playing games on the LAN. He reinstalled windows (which didn't fix the problem, and the computer restarted whilst doing this), and replaced the HDD, but is still getting the restarts.

I tried some spare (working) RAM in the computer, but this did not solve the problem either. I am leaning towards the psu (which is some cheapo Colors 550W job), though the computer doesn't power off, but just restarts, could this happen with a psu on its way out??

Other than that I'd guess at the mobo, though maybe the RAM is a poss still, though the replacement ram definately was fine when i memtested it recently.

To be honest guys I am stumped, would it be worth testing his existing ram to exclude it? Is there arnything testable that I've missed

Specs:

XP1500+
MSI KT600
2x 512 elixir RAM
160Gb Maxtor HDD
ATi Radeon 9500

cheers for any help


edit: forgot to mention, this has only started occurring since he moved his comp back to uni

 

[j00ni]

Unfortunately don't have any PSU spare, and I'm not overly keen to dismantle my pc to get at one

Am in the process of convincing him this is the most likely candidate, but didn't want to go get one without checking with you knowledgable people

 

[j00ni]

Being as he's a yorkshireman though I doubt i will convince him to get replacement ram and psu lol. Was thinking I'll re-memtest his ram, then if that's ok go for a psu (since the shop will probably be more happy to take that back than ram)

 

[j00ni]

I am pretty much convinced it's the psu now, since on closer inspection he has 2 hidden case intake fans which i didn't notice before (in addition to 2 exhausts) - god only knows why he thinks it needs so much cooling. Disconnected all that, and running it now with just hdd, dvdrw, cpu and gfx - and touch wood it hasn't reset yet

 

[j00ni]

Just an update, replaced the psu with a nice fsp jobby and it seems to be working fine, no restarts since 6ish, and given an intensive lan workout

So thanks for putting my mind at ease that i was going in the right direction, touch wood we are right