Hope This Helps:
I found this listing on eBay. I think the seller might be a member of this forum, although I don't know his/her handle on here.
I find it strange that the vac repairman is saying that the motor is "dead". If the motor had visible damage caused by, say, overheating due to seizure of any moving parts or fan bearings, he'd know it before even attempting to replace the carbon brushes. There would be some indication of something having gone awry...either burn marks or an odor of something having burned. In this case, it seems that he saw nothing else wrong other than the brushes (which, incidentally, neither he nor any of his affiliated stores had in stock).
Furthermore, if the fan bearings aren't seized (if they were, the motor would have "burned up" as I just stated), then the only other thing that could be wrong is that the motor's stator is damaged. The stator is a rotating "spindle" that makes contact with the carbon brushes to power the motor's armature. The armature only creates an electromagnetic field to drive the blower assembly (which creates the cleaner's suction), and it makes no contact with the motor shaft. If the stator was damaged, it would be immediately apparent to the repairman as it would show signs of excessive wear.
The carbon brushes are seated around the stator through spring-tension, and as the brushes wear down, the springs push the brushes forward to maintain contact with the stator. The stator does not wear down. The brushes need to be replaced when they are worn down enough so as to no longer make contact with the stator (thus not completing the electrical circuit to the motor).
The only thing I truly suspect is that the repairman is not reconnecting the wires correctly. If the terminals connecting power to the machine from the power cord to the switch to the motor/PN are not connected to the proper leads, the cleaner will not run. The neutral for the PN and motor are piggy-backed on a siamese connector. This is likely what he could be connecting improperly, thinking it's the hot lead.
Anyway, sorry for babbling...I have a passion for knowing how electrical devices work. Here is the link!
Brian
http://cgi.ebay.com/Genuine-Electro...823?pt=LH_DefaultDomain_0&hash=item483c6caa8f