Sony SL-HF750 play/FF issue

[KekkyLekky]

I found a Sony SL-HF750 deck today (drawer-loading) at a thrift store today and got it for dirt cheap, but it unsurprisingly has issues.
As I was getting the deck off of the shelf, a customer explained to me that the deck had been there for six months and was originally priced higher until "someone broke it," and now, the deck rewinds when "play" is pushed. His testimony was true, but it seems to be a symptom of a deeper issue. The mechanism does go through the motions to play a tape when the play button is pushed, but only for a second, and then it rewinds instead. Pushing the "fast forward" button results in the mechanism advancing the tape forward for a split second, but then stopping, and at that point, the only function that the deck will allow you to do is rewind.
So, it seems as if this deck has an issue with advancing a tape forward. What could be a cause for this? Since that customer said that "someone broke it," I wonder if there was something in the mechanism that was put out of whack when it was "broken."