I just picked this sweeper up today. I tested it at the thrift store, no whinning noise but I did notice it needed a belt. I get it home, changed the belt, started using it, and there is a small whinning noise now. I know it's not the motor going out becaus it would have done it wether there was a good belt on it or not, right? And I know it takes a U belt, so I'm jinda lost. Nothing should be touching the belt either.