Computer turning itself off - new build

[rich151087]

The problem:

The computer shuts itself down (as though someone pushed the power button on the case)

It's passed all stability tests. Memtest runs for hours without fault, same with prime95.

The computer will crash (or rather turn off abruptly) during light 2d use (e.g. playing video), regardless of whether a user is attending the machine or not

However, it never crashes when running prime95 and playing video at the same time.

When it shuts off, moving the mouse powers up the comp from the bios onward.

Basically, the system only becomes rock solid stable when the load is heavy on either the graphics or cpu or both, ensuring the PSU is having to work hard.

When the machine is not working hard enough to raise the cpu or gpu temp, it crashes.

Main spec:

AMD X2 3800+ (AM2)
ASUS m2n32-sli deluxe
Win XP

What I'm looking for is anyone who can explain, if the PSU is the problem, why the computer is unstable at light loads, but stable at high loads - the opposite of what you'd usually expect!

 

[Andy298]

The problem:

The computer shuts itself down (as though someone pushed the power button on the case)

It's passed all stability tests. Memtest runs for hours without fault, same with prime95.

The computer will crash (or rather turn off abruptly) during light 2d use (e.g. playing video), regardless of whether a user is attending the machine or not

However, it never crashes when running prime95 and playing video at the same time.

When it shuts off, moving the mouse powers up the comp from the bios onward.

Basically, the system only becomes rock solid stable when the load is heavy on either the graphics or cpu or both, ensuring the PSU is having to work hard.

When the machine is not working hard enough to raise the cpu or gpu temp, it crashes.

Main spec:

AMD X2 3800+ (AM2)
ASUS m2n32-sli deluxe
Win XP

What I'm looking for is anyone who can explain, if the PSU is the problem, why the computer is unstable at light loads, but stable at high loads - the opposite of what you'd usually expect!

Hmm, bizzare that!?
So it reboots itself on light usage? Is this when doing a certain thing? Can't seeing being hardware if it's fine under stress. Try safe mode see if it happens there also.
What you can do also is go into your system properties, advanced tab and Startup and Recovery Settings. Untick Automatically Restart. This will prevent your PC from rebooting if it's some sort of software issue. You'll get a blue screen instead with an error and you can take it from there really. Search on google to see what the error is.

 

[rich151087]

Automatic restart has been disabled since we installed XP. The pc doesn't restart itself, it just turns off like pulling the plug from the wall, but the mouse reactivates it (goes through normal booting process).

Light loads such as using video is a good example.

 

[Mekrel]

Load fail safe / optimised bios settings, and see if that works. Then try making sure you have all updated drivers. Also try booting with minium USB/Port devices and add one at a time.