Unfortunately, the diagnosis of yesterday's black screen is that the ledge camera has died. For the time being we are streaming the nestbox feed in its place with sound from both the nestbox and ledge. We actually already have a replacement camera for the ledge view waiting in the wings, as we had anticipated its demise based on its age. Weather permitting, we will install the new ledge camera very soon, as well as continue to pursue a new computer in order to restore both streams prior to nesting season. Thanks for every one's patience!