Ensure that your Sentry is powered on. Remove the base plate if it’s on. You should find a reset button with a “RESET” text to its left between the two terminal screws at the top of the camera body. Long-press the reset button until you hear “system reset.” After about 30 seconds, the Sentry video doorbell should power up again and you should hear “system startup” and “waiting for connection.” You can now set up Sentry in the Bosma app again.
Ensure that you hear “system reset” after long-pressing the reset button, and that you hear “system startup” and “waiting for connection” afterward. If one of these messages was not heard, please contact customer support.