After 6 years, the camera inside Box1 has become distinctly temperamental. I've checked all the cables and joints but it still produces a black image at increasingly frequent intervals. When tested out of the box, the only thing that puts it right when it is in a black mood is a good thump - not to be recommended - and not possible when it fails in situ!
We have decided to replace it with a new camera of the same type and today, only 24 hours after I ordered it from BoxWatch, it has arrived! What we couldn't know when we planned this was that a great tit pair would take over the box so rapidly after it was put back up, and that the male would start roosting in the box over night!