There is one other simple possibility. You say the problem started when you unplugged all the wires and moved the system. Having the mouse and keyboard wires switched will cause some systems to lock up. Did you check this? I'd also remove the case and inspect the network card to be sure it's seated properly. The best way to do this is to remove and replace the card.
If your system still won't boot, and you want to continue here, we really need to take a look at your boot log before we make any changes. Everything we've done to this point has been non-destructive, and I hesitate to start making changes without first identifying the problem.