XPS 700 Death

Hello all,

I have searched and searched and still cannot find a solution to this problem.

My XPS 700 won't turn on - not for more than a few seconds. I hit the power button and it boots into Bios, but after few moments it cuts out to nothing - similar to if you just pulled the power plug out of the wall socket. It's pretty much impossible to run it long enough to do any sort of diagnostic scan. The more times I start it, the quicker it cuts off.

First I thought it was an electrical problem, like the cpu wasn't drawing enough current from the wall. I unplugged everything and ran an extension cord from the other end of the house to see if this was the problem. Plugged it right into the psu and  the same thing happened. Next I moved the cpu to the other end of the house and plugged it in directly, Nothing.

Next, I thought it might be a busted fan so I took the case apart and checked the 3 fans. They all worked fine. I pulled the video cards, ram, sound, network, and stripped it down to everything but the psu and the mobo. Still won't start. So it's either got to be the power supply or the mother board, and I doubt the computer would even turn on and boot to bios if the mobo was bad.

I finally can get on the web using my girlfriend's mac to do some searches. It seems like others have had this problem, it's specific to the XPS line. But it seems like there is no solution (that I've found). I was about to buy a new psu, but from what I've read, replacing the psu does not fix this problem. I bought the computer in early '07 and it's already died on me.

If anyone has any tips I would really appreciate it. I'm already looking into a new Mac to replace what I thought was a computer that would last me at least a decade. I do video editing for work, and cannot go without a computer to view footage.

Should I bother replacing the mother board and power supply if I have the sneaking suspicion it could very well happen again? What to do?

Thanks!