What faults can appear with metal buttons?
General waterproof metal buttons can be used in a moisture environment for a long time, but some faults will inevitably occur after a long time, such as blown fuses. In this case, you can check whether the circuit board components are burnt; such as metal buttons switching load capacity is poor. In this case, you can use a multimeter to check whether the current limiting resistor and the diode high-voltage filter capacitor are faulty, and then check whether there is virtual soldering or line de-soldering at each connection on the circuit board; such as metal voltage output of the button switch is unstable. In this case, it is necessary to check whether the electronic components of the high-frequency transformer are damaged.