G4 doorbell stop working on external power

My Aqara G4 doorbell has suddenly stop working on external power. It has been wired into the external power supply for the last 12 months but last week it has stopped. I have checked and it is still receiving 12v it works if I install batteries but is sucking them dry unacceptably fast.

Hello @alex138
Try removing the batteries and resetting the G4 to factory settings. Connect an external power supply and re-add the doorbell to Aqara Home. Make sure the contacts are not oxidized and are tightly sealed and not touching each other.