Someone mentioned you can fry a CPU in a very short amout of time, it just takes a few seconds, actually. However, that is if you don'd have a heatsink. If you had a heatsink on, it definitely should not have fried in 20 seconds. Does your internal speaker beep? Do you have any lights come on on your keyboard? It could be your motherboard. If you have a friend with the same socket motherboard, swap the CPU. This next move is a little risky, and I'm sure someone's going to reply saying "Don't do it", but here it goes. A quick way to know if you have power going to your processor:
Have someone to unplug/ turn off your CPU switch. Turn your computer on, with your finger very near or on the clean, heatsink-less CPU. It will get extremely hot within a few seconds. There shouldn't be more than 2 seconds between the time you turn on your computer and the time you swithch it off or unplug it. It'll burn the crap out of your finger if you're touching it and leave it on too long. It'll also fry itself. Sometimes, it'll look like your mobo is working properly, but my problem with my last mobo is that it was providing absoluely no power to my CPU. Yes, my PSU was working properly. Don't try it if you don't feel confident.