Shutter Panel ( bingo )

A thin wooden board mounted to the bottom of the playfield. When slid away from the player, holes in the board would allow the balls to drop beneath the playfield onto another sloping board, which would direct the balls into the ball trough. The shutter panel normally closes when the first ball lifts the ball gate on a completely reset machine. Complete reset of the machine requires all balls to be in the ball trough, so if you power off a game with a ball in the ball runway, then power on and start a game, shooting the first ball will not close the shutter. Once all the balls are beneath the playfield, reset is complete and shooting the next ball will close the shutter.