Hi Tweakie.
Thanks for your reply sorry about this but i poster the incorrect information.
each stepper motor is running on its independent gecko drive
both gecko drives are connected to a PMDX -122 to the same connector J3
the cnc have been running for the past 7 years with no problem.
so not sure how do i go about solving this problem.
both motors are turning just one need reversing .
does your reply still stand? if so can this be done off the gecko drive?