Good point Peteski. She came in brand new and this was the problem from the very start. No matter what, once cold, she started the same way.
PowerStroke: Now that we know, it was most likely a factory defect. But I wouldn't worry about Atlas product quality just yet.
This is the first time ever I've heard of a broken brush in a new Atlas loco. Tens of thousands of their locos don't exhibit that problem. Quality does matter, but this seems like an isolated incident. I have a feeling that if mecgp7 would ask Atlas for a replacement brush (after explaining the situation) he would receive one free of charge.