Going Up? Z Axis will only go up

I agree with @ScottWillis, seems like a gShield issue… other than testing and tweaking the amount of power to the Z-Axis with the pot I would contact help@ inventables dot com

(there is a too high and a too low for each of the pots… so test both ways and take it nice and slow and move in small increments)

Edit: See here for more detail except adjust the Z -