Make sure your CPU Heat sink is seated correctly, memory is pluged in corectly and you have sellected what FSB with the jumpers your chip is. also check the cpu fan is pluged in.
I had this problem a few years back and was my first build. The Heat sink and fan (HSF) was not seated correctly and I had done the cpu in so it didnt boot. Asuming you have check the PSU is working and the power cord is working first.
Somtimes the easy things get missed like the switch on the wall or PSU or the fuse has gone in the plug.
Good luck.
tez
October 2004