Most likely X-Axis armature cable. X-axis cable flexs when Y-axis moves. Difficult to swap axis connections to motor, need to switch armature, encoder and connection from control to drive. Cannot run machine, control may run away if rotation direction is different. Also if cable or motor is bad may damage drive. Take out motor and hi pot test. same to armature cable dissconnect from motor and drive. A resistance test will typically only show a short, not failing insulation. Inspect cable for cracked insulation. Oem cables were not the best for the app. need hi flex w polyurethane jacket. Also if one cable is bad replace both replace armature and encoder.