So I recently purchased a 1971 #Bally Mariner as my first pinball machine, it is mostly working, but when played in one player mode after a ball drains the machine sometimes plays the next ball as player two, and the next as player three, (never four though?). The machine also sometimes replays a ball after it drains despite the "same player shoots again" light being off. These occur regularly, but are not consistently. Sometimes the machine will work as intended and other times it will not. I suspect some sort of sensor or something is dirty and works only some of the time, but I have little experience fixing pinball machines. I appreciate any advice of any kind. I can take pictures if that helps. Thanks!