I have experienced this. It happened when using the recall to switch back to HGTV. Interesting thing to note is that it read "Delayed Live TV" at the top of the banner where it normally says "Live TV". I'm not sure why it said that but it must have something to do with it. This issue happened when I had a recording going on another channel. When I stopped the recording it fixed itself and no more black screen. Did you have anything recording when you experienced it?