Roborock Onyx4 Mainboard for Empty Wash Fill Dock S8 Pro Ultra PCB

The Roborock Onyx4 mainboard is an original electronic PCB designed for the Empty Wash Fill Dock used with the Roborock S8 Pro Ultra. As a core control component, this board supports the dock’s key operating processes, including water management, wash functions and internal system communication. It is intended as a precise replacement part for restoring correct performance and maintaining the reliability of the docking station. This new mainboard features a green printed circuit board construction with integrated control electronics, cable connectors and JST-type connection points for secure installation.

Built as an original part, it is engineered to match the technical requirements of the Wash Fill Dock and ensure component-level compatibility with the Roborock S8 Pro Ultra platform. Its layout includes multiple ports and mounted electronic elements that coordinate the dock’s internal functions with accuracy and stability. In practical use, the Onyx4 PCB acts as the central control board responsible for processing signals and managing communication between dock subsystems. It helps regulate operational sequences related to washing, water filling and connected dock mechanisms, supporting smooth interaction between hardware modules.