ok so yesterday my computer was running just fine and I was about to play some World of Warcraft when all of a sudden the computer just shut off. I tried restarting it but nothing happened. So I pulled off the cover and checked around to see if anything was not connected right, which it all was. I then use some airspray to clean out all the dust. I pushed the power button again to see what happens INSIDE the case and I noticed the fans twitch evertime I press it. It's like they turn on for a second then turn off. So I figure either my Power Supply died or worse, my motherboard. Any ideas from you guys?

My system specs:
AOpen Motherboard (don't have the specifics but I can get them later if needed)
AMD Athlon XP 2700+
A HIGH performance fan/heat sink connected to the Processor
768 3200 DDR
160gb MAXTOR Hardrive
Radeon 9800 Pro
2 system fans (one shootin in from the side, one shooting out from the BACK)
I haven't overclocked anything on my system either.Did you smell anything.. Funny?

I suggest you test and/or replace your Power Supply Unit.check the connection from the psu to the motherboard some have an habit of coming adrift....