Z axis motor not working

[Paul C]

All is freely running but the right Z axis motor will not turn. I have disconnected the screwed rods so there is no load.

As a diagnostic, I swapped the z axis leads over and now the right hand motor runs but the left is stopped. The motor is ok so I tried different leads and the lead is OK. I plugged the x motor into the z socket as a diagnostic and that does not work. Any suggestions please. Could the problem lie with the connection socket on the mother board

[William]

1. Re-burning the firmware. You can try to remove the A-axis drive plate A4988 first, and then exchange with the other axis to see if the root cause of the issue is A4988
2. If the issue persists, then you can determine the problem is the motherboard, you should contact the related sales staff.