I have a Gottlieb System 3 Super Mario pinball with an issue. I recently acquired this machine and when I went to pick it up it would play an endless number of balls. The game never ended. I brought it home did a factory reset and it played well for a few games. Now in the middle of game play, it will either kick out another ball into the shooter lane or end the current ball play, shuts down the flippers and kicks another ball into the shooter lane. What would be good to check.