Build turning off almost immediately after boot

MickR

Distinguished
Mar 26, 2010
2
0
18,510
Hi all,

I've recycled a few of my old bits and pieces for a friend of mine, and when I boot it, it turns on, almost immediately turns off, and then won't turn on for a good 15 minutes.

Specs are:
Asus P5QL Pro with a Q9550
4GB Ram
Brand new CORSAIR CX 750W V2 PSU
XFX Radeon 5970

I've tried plugging out everything except the CPU and RAM, and same thing happens.

However, when I tried the old PSU, it started up and stayed on. The old PSU doesn't have the 8pin PCIe connector the 5970 requires unfortunately.

Is it the new PSU like I think, or is there something I'm missing?