Hitachi excavator accessory 9226743 computer board; Main board PVC

9226743 is an engine control computer board (motherboard) used on early Hitachi ZAXIS mid size excavators (mainly ZX120/ZX130 series), which is the core control unit in the electrical system. This computer board is mainly responsible for: collecting engine speed and load signals, automatic engine control (Auto Engine Control) related logic operations, signal interaction between monitors, sensors, and solenoid valves, fault code storage and diagnostic output. When the following situations occur, this computer board usually needs to be checked or replaced: the engine cannot start normally or the automatic idle failure monitor displays engine related fault codes with abnormal action response, the engine speed is not controlled. The computer board itself is flooded, eroded, and the interface oxidizes, causing signal interruption