The other day I pulled my son's motherboard (a KT7A raid) to install an I/O shield (that rectangle with holes for the keyboard and mouse connectors, USB connectors, serial and parallel ports,etc). When I tried to power up after replacing everything, nothing happened. I figured that I must have broken the motherboard somehow. I got a replacement (same type), installed it, no luck. I swapped out the power supply; still nothing. I swapped processors; no luck. Yes, it is plugged in! I have checked all of the connections and they all look tight and in the right spots. Does anybody have any ideas what could be the problem or what to check?