Desperate for ideas-z axis only goes -

I have a bridgeport series 1 cnc running on gecko 203v drivers (3 axis) ...pmdx-134 and pmdx 126 on windows 8 using the mach 3 (32 bit os) runs off of a ess smoothstepper. z axis only moves in the - direction, drivers check out...new bob , new motherboard. reinstalled mach3 wiring correct on motor. cannot for the life of me find why it is doing this........i change y and z......same problem(obviously on y) any ideas.....anyone.....please help-CAM4GE

have you checked your setting in" port and pins "