Here is the Hydro Spa HS55 Circuit Board, Chip # HS55R1_. Used in 52519 Control Boxes.
Many Circuit Boards look alike, Please be sure to check the Chip Number and or Balboa Part Number to be sure this is the correct Board you need, as Boards are not a returnable item, only for warranty situations. If you have any questions, feel free to contact us, we are happy to help. Thanks.