Although I haven't seen a schematic for the 2250, I have a 4750 which started running to fast (held the platter from turning). I had burned out a transistor which regulates the speed. As I recall it was very easy to replace and very acessable (had to be if I did it).
If this happened all at once (or someone held the platter still) I would sure look into it. I ordered the transistor from Mouser Electronics, they were really cheap (shipping cost more than it did).
Anyways something to look into.