Doorbell not ringing in house

I have hardwired Ring 2 doorbell that is attached to wall next to my front door. Until some weeks ago the doorbell rang the in-house doorbell every time the doorbell button was pressed. Now it does not do that. If I place steel screwdriver across the 2 screws/wires that connect the back of the Ring to the house (it replaced a previous doorbell), the in-house doorbell dings (not digital melody) just fine. I have never charged the battery since installation and it is now on the charger, but I suspect the battery has nothing to do with ringing the in-house doorbell, so I suspect the Ring doorbell itself has gone bad. Video still works and we get the notify on my wife's phone.What to do? Also, the little Ring book that came in the Ring box shows battery charging colors as green and red. When I plug it into the charger it shows green and amber. What's with that?