Problem (building pc)

is everything connected correctly (especially thinking about an extra power cable to the bobo you might need apart from the 20/24 ATX connector). try rresetting the bios. are you trying with just 1 stick of ram (guess thats already the case) cpu (hsf is applied correctly) and vid card, leave everything eslse disconnected. is you psu working properly? can you try with a replacement one (other pc, one of a friend, local pc shop, etc.) is there an intruson pin/jumper on your mobo? try shorting these to boot. are fans attached? my mobo need due to some ununderstndible reason a cpu fan a a case fan to be connected to boot (maybe there is somthing like that in the manual)

if you cant get it to work i would suggest taking it to a local pc stort to let them take a look (they will here in switzerland for a small fee of roughly 15$ (convertred)).