Working through issues with my Stern Stampede and am having issues with the Bonus Stepper coil as it steps up and staying energized when you start the game or sometimes in the middle of the game. I have cleaned the stepper unit but it is an intermittent issue. I am guessing it is a switch that is holding the coil energized but I am not sure where to start? I do have the schematic but I have very low knowledge of how to read one but I am learning. Thank you in advanced for the help.