Went to start a new cut today and the Z-Motor is reporting a position of 0.0. Went in to recalibrate it and whenever I raise and lower the motor, the motor moves, but it never updates it position in GC. I’ve run the motor tests, the Left and Right motors pass but the Z Fails.
I was running on firmware 1.13, so I updated to 1.15 to see if it helped… it didn’t. 
Suggestions?
Have you checked to see that the connectors are firmly seated? I’ve had trouble keeping the cable plugged into my z motor…
Yeah, i unplugged it and reseated it.
I also rebooted the whole system to make sure it wasn’t erroring somewhere internally
If you swap the z cable with one of the other motors on the board, which one fails?
Good suggestion, I just tried it. Switched it with the Left motor, now it thinks the left motor(really the z motor) fails and the z-motor passes( really the left motor)
It’s defiantly something wrong with either the motor or the wire.
I wish i could swap the wire completely but the head going into the z-motor is smaller than the one going into the left/right motors
I just sent off an email to support to see where i go from here.
If you have a meter, you could check to see if one of the wires in the cable is at fault. There has been at least one instance of that in the past. It would determine whether the motor or the cable needs to be replaced.
Bingo! Tested the wire and the yellow wire was not working.
Not sure how the line got sliced, but patched it up and its working now.
Thanks for the insight
I had the z-cable coming from the bottom until i dropped a ply sheet and the cable and my toes survived. Since then the z-cable comes from the top, but I still wear flip-flops 
. I’m just more careful were I have my feet. Good you found the source. Happy chipping!
There’s a certain satisfaction to finding and fixing something like this. 
Safety third, right? (Behind comfort in your case.) 
