Yes, to me it sound like it's on its last leg. Over time (depending on use) the coil/armiture within the motor itself start to go. It could even be a worn shaft. Try this, turn it on until it's moving, then change speeds until it stops. Go outside to the blade and move it buy hand. If it starts agian by moving it, I would think that the magnetic field within the unit is shot.
Good news: There should be alot around. (I think)
My input anyways..