ATX power supply keeps blowing fuses...

[Kaieye]

There was a power surge or outage two weeks ago in the Bay Area and
a customers box stopped working. I exchanged out the old power supply and installed a new one. It seemed to work for a few days on and off until a few moments ago. I might have heard something electrical short or buzz and now the box is dead. I pulled out the old power supply and check the fuse and it popped. I installed another power supply and the box is still dead. Any ideas? I suspect that the mb is shorted and dead. What do you think? Could
the power switch be broken or shorted??

 

[medic]

Sounds like the board to me as well.

 

[jamarno]

The motherboard may have shorted one of its bypass capacitors to ground. Another possibility is that the onboard regulator for the CPU shorted a transistor (all transistors should be checked then because the bad one takes out its partner).