Ring doorbell stopped charging

Our Ring (not 2) suddenly stopped charging with no change in the system. The voltage at the terminals is 20 VAc and the interior doorbell no longer rings when the Ring Doorbell is pressed (the Ring does chime). If I short the terminals, the interior does ring. The Health now shows Battery as the source.It appears that the Ring doorbell is no longer making contact internally (I did replace the mounting plate). Is there a test I can make to the Ring doorbell: get a reading from the three sets of contacts? Chect the contacts on the place (not the termanals since the doorbell does ring if shorted and there is 20 VAc).Also, our Ring has three sets of contacts - not two as seen in Ring images.Thank you...