try unplugging all usb devivces, put the cmos clearing jumper to the 'reset position' and try turning on the pc. these newer intel boards will fire up and reset the cmos, then tell you to put the jumper back to 'normal' position.
intel puts a lot of safety trips in their mainboards. if you go out of range somewhere, they like to freeze up and not restart until you compltely reset them. that, or leave it unplugged for at least overnight... that often works too.