system dies on its on

[jaylee]

I have a fic az11e mb and a 1gig thunderbird w/300w supply. It will lose power at different intervals of time.It will not power up until about 15 minutes later. It may run fine for 5 hours or five minutes. I used a friends 250w supply and it will power up immediately. Is this a bad power supply or a conflict between by supply and mb? All components are newly assembled.

 

[Supergax]

It is the power supply.