PC suddenly dead - PSU?

[phekdra]

For the last couple of weeks my machine has been randomly turning itself off, then turning itself back on again a couple of seconds later. It's been running stable for months but I tried a torture test and this caused it to turn off fairly quickly, totally unlike the reboots I used to get when I was overclocking it.

Then today it turned itself off and just sat there - the power button was dead. I turned it off at the PSU switch for a couple of minutes and tried again - I got a burst of activity for a fraction of a second, fans starting up, then dead again. Exactly the same thing happened when I tried it a couple more times. Now I have a card reader with a light on it that comes on when you turn on the PSU, and this light is working, so something is getting from the power supply. I've tried unplugging and re-connecting the power cables from the PSU to the motherboard with no luck. My suspicion is the PSU, but could someone give me a second opinion before I try and track down a replacement in order to test it?

 

[fobose]

Its sounds like the PSU. What sort of temps were you getting with the CPU though?

 

[phekdra]

Its sounds like the PSU. What sort of temps were you getting with the CPU though?

Not excessively high - 60 to 65 C under prime small FFT. While the machine was going through its off and on phase I reset everything back to stock frequency and voltage and it still kept turning itself off, so I was fairly sure it wasn't temperature or voltage. I suspected it was either the PSU or motherboard, but I might now borrow a spare PSU and see if that works - thank's for your help.

Four month old Corsair PSU too...

Phekdra