The most common event that causes an axis to not move is a loose set screw or grub screw in a pulley. With a small Allen Wrench or hex key confirm that all the screws in the pulleys and couplers are tight by attempting to tighten them.
Once the fasteners are tight - Slowly move the laser head by hand to verify that the drive mechanisms are free running and that they will turn the motors and that you can feel the notchy motor resistance a little bit.
The order of the motor and cable swapping is important. We should revisit that after the set screws and drive mechanisms have been checked.