In some implementations, the lens holder 1120 is supported by the infrared filter 1134 to protect lenses in the lens assembly 704 from being pushed when a user touches or presses the front cover plate 708. The doorbell camera 106 may include at least a sensor board 1108, a main board 1110 and a secondary board 1112 that are stacked within the device housing 702. In some implementations, the sensor board 1108 includes a connector 1108A that is coupled to another connector of the main board 1110 directly. Alternatively, a flexible cable is optionally connected to the connector 1108A for electrically coupling the main board 1110 to the sensor board 1108. In some implementations, two ends of a flexible printed circuit FPC 1126 are electrically coupled to a respective connector at the main board 1110 and the secondary board to couple them to each other. The sensor board 1108 optionally sits on a rear interior surface of the device housing 702.