I just finished my build last night, followed the instructions to the letter.
plugged in the usb uploaded firmware and configured software. turned on the printer all good, connected thru port 5 all good, went got a drink because i felt accomplished, 10 minutes later went to home the axis's, X all good, Y basically all good, lost com port 5 connection, printer disconnected, lcd went black and the printer is dead. 24Vdc power supply is putting out 24vdc the MKS board is receiving 24Vdc on both input pairs on board. USB cable and extension are working fine tested them against my standard printer. think it's a safe bet my MKS board died. or am I missing something. Wiring is exactly like the wire diagram provided.