I was running a program and everything was working well. I was cutting a deep pocket and the Z axis suddenly quit moving. Both X and Y work. When I home all, the Z axis DRO counts down, but the axis does not move. I can home X and Y with no problem. Is this a wiring problem?

I noticed when I tried to move the Z axis a few minutes ago, there is an audible noise when I press page up and page down, so it appears the motor is still getting electricity, but the head is not moving. I may have to remove the back shield and see if the motor is trying to turn. Do you guys have any troubleshooting tricks I should try?

I found out the coupler had come loose and slipped off the ball screw. An easy fix.