Send the command: STEPPER_BUZZ STEPPER=stepper_z

This will move the the z-motor in the front left corner anti-clockwise by a small amount and then return it to its original position. It will do this several times.

Send the command: STEPPER_BUZZ STEPPER=stepper_z1

This will move the the z-motor in the back left corner anti-clockwise by a small amount and then return it to its original position. It will do this several times.

Send the command: STEPPER_BUZZ STEPPER=stepper_z2

This will move the the z-motor in the back right corner anti-clockwise by a small amount and then return it to its original position. It will do this several times.

Send the command: STEPPER_BUZZ STEPPER=stepper_z3

This will move the the z-motor in the front right corner anti-clockwise by a small amount and then return it to its original position. It will do this several times. If the above described movements do not occur, power down and double check you wiring.