I frequent a bar here which has two 7 foot Diamond Smart Tables. The bar owns the tables; got them 3 years ago. He opens the tables for us to rent by the hour. Over the last few months, there has been a problem with the ball return/sensor. We first noticed that the 1 ball, and or the 5 ball would come to the cue ball return on almost every rack. Now the 1 ball will not return at all; so far he has lost four 1 balls; I presume they are in the tables somewhere. Any ideas?