Broken PSU?

[Luigi]

My brothers computer has been playing up recently, so I thought I'd ask here to see what your thoughts are.

Basically, when the switch on the PSU is turned on, the fan instantly comes on, as do the case fans etc for about 1/3second, before it all go's dark again (but the PSU fan continues), the system is off and wont turn on at this point.

I connected the PSU to a basic tester thing I have, and all the rails showed as working, apart from the -5v... does the -5v turn off when the PSU is turned on.

My thoughts are that either the PSU or mobo have gone..

TIA

 

[JN]

IIRC -5v hasn't been part of the ATX spec for quite some time. Easy way to tell if the PSU even has it is if there is one wire missing from the ATX connector.

Either way -5V was only used for some really old soundcards and other addin boards, and shouldnt be affecting it.

Not to say the PSU isn't fubared anyway tho.

 

[Luigi]

ahh bum, I have a feeling it might be the motherboard then, as the PSU is being powered up with nothing happening...