The prize sensor on Grab N Win is comprised of three infrared sensors mounted to a bracket that cast a beam across the the prize chute to hit a reflector on the opposite side, when the prize is dropped the prize breaks the beam to indicate to the main board that the game has won a prize. The prize sensor is checked by the crane during the boot sequence of the game by dropping the claw down until the claw breaks the beams. If the game does not see the beam get broken during the boot sequence it will generate an error 7.
Grab N Win - How to check the prize sensor.
