This board plugs in in place of the existing driver board, and allows you to see all of the outputs (lamps, solenoids, sound outputs) on 65 LEDs. If you need to troubleshoot your game, or want to build a test rig on your bench, this board will allow you to troubleshoot the driver outputs.. you are in reality debugging the outputs of the MPU board. Due to the fact that this is a test board, we will replace or repair it, but will not accept it for a refunded return.