Once had a Melbourne dealer tell me that a shaker motor was working on a game. When we opened up the motor at home the brushes were non-existent. Not sure what black magic/dodgy repair had that motor working for him, but must have been true because he confirmed it with his tech by phone while I was there, right in front of me!  

At the time I chucked to myself at the dodgy used-car tactic, not concerned as the parts were there and we'd sort it soon enough.