What can be the cause and what are the possible countermeasures if the buzzer does not sound?

- Jan 20, 2019-

There is a smoothing capacitor in the internal circuit and it is possible that inrush current has caused the switching power supply to overload, resulting in no outputs.

Possible Countermeasures´╝Ü

If there is a switching power supply overload, it is possible to reduce the inrush current by connecting an external limiting resistor in series.