A4988 Stepper Motor Driver heat problem

We want to drive two stepper motors ( pololu.com/product/1183. Unfortunately, after a few seconds we observe that the same motor driver(shown as 1 in the figure) heats enormously and produces erratic moves. We have in total 6 A4988 Stepper Motor Drivers. Five of them have constantly the heat problem and move erratically. The same stepper motor has neither heating nor movement problem. I do not think that 5 out of 6 motor drivers have problems.

I would really appreciate your help.

We solved the problem by adjusting the potentiometer on the board for limiting current. We did not realize that there exists a trimmer potentiometer on the board.

I am glad you got it working. Thanks for letting us know.

- Jeremy