Omnistep repaired

Hi All, fyi the omnistep on our motorhome wasn't working when we got it, but after checking it had power to it I removed the motor unit and tried to power it up on the bench with still no movement either way, so it was tapped gently with a small hammer and Bingo!! It now runs ok, the motor and gearbox were checked and lubed while off.
I think that one of the motor carbon brushes must have stuck away in the motor, as there is evidence of the steps being knocked when...