Aha! It looks like one of the main power supply connectors has come loose in shipping. It's possible that it was not fully seated and locked during assembly. It's a white plug with blue/black/red wires near the large, black capacitors. Simply plug this in to the only available connection on the power supply board (you can see an identical red/black/blue wire that is plugged into the power supply from one of the amplifier modules) and you should be good to go. The white connector is keyed so that it will only plug in in one direction and will make a click when it's locked. I'm positive that the amp will be fully functioning once that plug is connected.
