Erratic z axis servo

I moved my X Carve and now my z axis servo is acting erratically.
responding up and down when jogging the Z Axis on setup.
Any thoughts on how to diagnose?

A stepper motor need Signal (step pulse) and Direction, aside from power.
If one of the 4 wires is loose/have poor contact the stepper will operate as usual, but loose the Direction command so actual direction will be random. (Usually in the direction of least resistance)