Check the listing for details. Cornelius 620521775S Control Board, Downlight, Merchandiser, Viper. Condition: New. Listed at 49.99 USD. The Cornelius 620521775S Control Board is a key component for managing and controlling the operation of a frozen drink and slush machine. This control board is designed specifically for use in restaurant and food service settings, making it an essential part of any bar or beverage equipment setup. With its compatibility with various Cornelius products, such as the Viper downlight and merchandiser models, this control board ensures seamless integration and efficient functionality for businesses in the food and beverage industry.