P4PE not powering up

Basically, this board was given and I think it has potential to work again. I can unsolder and solder the parts.

Here's the deal:

This motherboard has not had any problems until a SmartPower 2.0 failed. The caps in the PSU was shorting out, so the board was having pusling power. I could even see the LED's light act. So, they replaced the PSU. Apparantly, the guy had problem with the mouse not powering up. I decided to take a look, to find that PC was off and wouldn't power on anymore. I tried the PSU by itself and worked fine. The board is toast, but can still recieve power, as the green LED is still on.

Looking at it's caps, they look good to me, but I think the voltage regulators too a smack from all that pulsing. (The PSU was on for a long while)

I now own the board and can replace the voltage regulators from a fried S478. The board in question is irreparable, as the circuity of the spark litterally went off.

What can make the P4PE to not power up?

 

Anyone? This board is good looking!

 

Come on, I'm sure someone can answer that!