Z-Motors Only Rotate In One Direction.

[Carabella22]

Have been testing our new GeeeTech I3 Pro. The motor for both the X and Y axis are working correctly. The printer bed or (X) moves in both directions correctly. The extruder or (Y) axis moves in both directions correctly. However, both Z motors only rotate in one direction. If you press the down arrow via the manual controls on the Repetier program the motors move the Z axis down. If you press the up arrow the motors move the Z axis down. We have tried to trouble shoot the issue by changing the motor leads to other motor plug positions and the motors will rotate clock wise and counter clock wise. If you plug the X or Y axis motor into the either Z port, that motor or axis will only move in one direction which is the same issue we are having with the Z axis. This seems to imply there could be something wrong with the Z axis wiring ports on the control board. We think we have narrowed the problem down to either a hardware issue with the control board or a program/firmware issue. I did update the firmware this afternoon using George Robles Jr's link for the "Geeetech Prusa i3 Pro B 3D printer Firmware for GT2560" for the Arduino Mega 2560. The problem with the Z-motors still persists. Has anyone else ran in to this problem or could anyone help guide us on how to solve this problem?

Thanks

[William]

Have been testing our new GeeeTech I3 Pro. The motor for both the X and Y axis are working correctly. The printer bed or (X) moves in both directions correctly. The extruder or (Y) axis moves in both directions correctly. However, both Z motors only rotate in one direction. If you press the down arrow via the manual controls on the Repetier program the motors move the Z axis down. If you press the up arrow the motors move the Z axis down. We have tried to trouble shoot the issue by changing the motor leads to other motor plug positions and the motors will rotate clock wise and counter clock wise. If you plug the X or Y axis motor into the either Z port, that motor or axis will only move in one direction which is the same issue we are having with the Z axis. This seems to imply there could be something wrong with the Z axis wiring ports on the control board. We think we have narrowed the problem down to either a hardware issue with the control board or a program/firmware issue. I did update the firmware this afternoon using George Robles Jr's link for the "Geeetech Prusa i3 Pro B 3D printer Firmware for GT2560" for the Arduino Mega 2560. The problem with the Z-motors still persists. Has anyone else ran in to this problem or could anyone help guide us on how to solve this problem?

Thanks

Hi,
Looks like the driver module A4988 has a problem.You can ensure that via swapping the A4988 of Z axis with the one of X axis(or Y axis),cuz you said X motor and Y motor rotate nomally.Afer the exchange,see how the Z axis and X motor(or Y motor) go.
Regards