Check if the handle of the button switch of the handle button is disconnected. If the terminal does not fall off, please operate the button switch with both hands to see if the circuit board button indicator is on. If it is on, the switch and circuit board are normal. Broken, please continue to check, use a multimeter to check whether the transformer has 24V or 30V power. If there is no power, please continue to check whether the primary voltage of the transformer is 380V. If the primary voltage is available, please replace the transformer at five points.
To fine-tune the positioner for short circuit, you can use a multimeter resistance file to check whether the resistance of the positioning terminal is normal (0-1 value is normal, if it is not within this range, it is abnormal).
If there are no abnormalities after completing the above points, please continue to check whether the solenoid valve is stuck. If the solenoid valve is stuck, you need to clean the solenoid valve before installing it. If it is still not used after cleaning, you need to replace the solenoid valve.