Stepper motor only moves in one direction

[tinatzk-0]

I recently purchased a GEEETECH 3D Printer Pro B and was able to get it built successfully, but when I tried printing the extruder motor would not push the filament through. I was able to track the issue back to the stepper motor driver by moving it to the x-axis slot. When testing it on the x-axis the motor it would only move in one direction and just twitch in the other. After doing a little searching online I was to find a link to another thread
(viewtopic.php?f=17&t=17038) stating that it might be the voltage settings of the stepper driver. I tried turning the potentiometer to adjust the voltage, but it would only switch to 0 volts or 4.6 volts. I was not able to adjust it down to .8 volts like the other drivers. So I am thinking that I received a bad stepper driver, unless you can think of another fix for the issue.

The stepper motor driver my board came with is the A4988. See attached image.

[Cup]

If you don't home the printer after you start it, all the axes will regard the original coordinates as the home position and will only go in one direction.

[tinatzk-0]

I did home the printer when trying this. After homing I was not able to move the x-axis to the right it would only move the the left when I tell it to move left after manually moving the motor to the middle. I tried moving the x-axis through both the computer interface and the printer's interface. If I leave the potentiometer set to 4.6 volts everything works as expected and the motor moves in both directions, but it runs louder than the rest. I am assuming it is not good for the stepper motor to be running at 4.6 volts.

[William]

the voltage should be 0.8-1.2 V.if the voltage is much more than the value,the motor's temperature will be high.

[tinatzk-0]

Ok, I just wanted to verify that. I think I received a faulty stepper motor driver then, because even turning the potentiometer a 1/16 turn in either direction drops the voltage down to 0 or 4.6 there is no middle ground. I cannot get it set to 0.8-1.2 V.

[bang]

So did you try swapping a driver for your X motor to take a look?
Maybe the one of X was broken.

[tinatzk-0]

Yes, originally the extruder motor was the one having the issue. I swapped the that stepper motor driver with the one for the x-axis and then x-axis had the same issue and the extruder motor was fine. It would only move in one direction, I think this was because the driver wasn't supplying enough power because of the bad potentiometer. I tried adjusting it but I cannot get it set to .8 -1.2v volts.

[bang]

If that is the case,i guess you can ask your seller to send another one?