So far, we've swapped out the pump, the motherboard and the commander core and it all ends the same, so I'm not so sure the pump is to blame
Attached is a picture of the pump when the system starts. I get the same color pattern if I start the pump from the PSU disconnected from the motherboard. The fans turn on, but I can't tell whether the pump is working and moving fluid through the radiator.
The motherboard does not seem to recognize the tach wire from the pump, regardless of whether I connect it to the AIO_PUMP or W_PUMP+ port. In either case the bios reports nothing on the connected port.