I have a new Sainsmart CNC Router 3018-MX3 assembled and Mach3 installed. Control board has a red and green lights on. The spindle motor spins when running a supplied g-code file. The stepper motors do not move in x, y or z directions. Actually there is no sound from stepper motors. The Mach3 screen does shows X, Y, & Z movements when using the jog functions. Any tips/suggestions as to how I trouble shoot this problem.