Have you swapped the wires between the Z stepper and the miniRambo with wires from either the X or Y? At this point if the problem moves the issue is within the wiring, if not it’s the Z driver.
Have you swapped the wires between the Z stepper and the miniRambo with wires from either the X or Y? At this point if the problem moves the issue is within the wiring, if not it’s the Z driver.