I am putting a fourth axis on my table top, deep groove, milling machine

 It was working but I wanted to fine-tune the movement of the motor  and ended up changing something to the point where all the motor does now is vibrate when I try to move it.

 I have tried everything I can think of but I cannot get the motor to rotate the way it did previously.

 The motor is a pacific scientific.  5 V DC motor with 1.8° per step, 200 steps per revolution

 Any ideas as to what I have inadvertently changed would be appreciated.

 Thanks, Chuck