Yeah the parts are the same. The upgrade from the V-Tower to the Extreme amounted to adding the digital controller, and fan, etc. for bag use. I'm thinking that the defective parts can be replaced. He may even offer an upgrade at a nice price.
Where the hell is the new digital V-Tower anyway? Someone, on some forum, reported buying one from a shop about a month or so ago. He said he paid $200 for a digital, whip only V-Tower. That had to be the new V-Tower unless some headshop was selling the Extreme without the bag setup for some reason.