One of my co workers has a Vitamix brand vacuum. The motor recently died in it. He has kept the filters and bag clean over the years. He would like to get it up and running again. Do the motors on those have the standard carbon brushes? or a motor similar to the Rainbow induction type motor. Also how difficult is it to service. I repair vacuums all the time at work so fixing it wouldn't be an issue if I know what I'm up against. Any advise would be appreciated? I'm thinking it is just a motor carbon issue at this time.