Problems starting...HELP

I recently bought a Barton 2800 and a Aopen AK79G Max motherboard from newegg and i put it all together and the computer will immediatly shutoff, i have tried reseating the processor a few times with no luck, all that i have hooked upto it is a 450 watt ps, the barton, the heatsink and fan, and then the board, no ram, videocard, hd or anything else...im not sure what it could be besides the board or the processor...any help would be greatly appreciated.

Using onboard graphics? What kind of RAM are you using? Single... dual?

donno that mobo, but I know mine will automatically shutoff if theres no CPU fan detected, or no RPM's from the CPU fan detected.... if your fan on your heatsink came with a 3 pin connector, make sure its plugged into the CPU fan spot on the motherboard, or.. if its a 4 pin molex and had an alternate yellow wire with a 3 pin plug, make sure thats plugged in also...

safety feature.. donno if its defaulted on yours..

alrighty thanks guys but it turns out that my brand new 450 watt power supply just didnt work, so i just got a new one and all works fine.