We had a player go blank because I messed up on the conditional playback tab dates and all of the assets expired. It did not show the checkbox on the screen (which would have been worse!) because it had content "scheduled", but it had nothing to play because the assets were all expired. It was just blank.
An inexperienced support tech saw that the playlist in the Schedule tab was green, and thought that content should be playing (so he thought it was a hardware problem with the Samsung screen). It would have saved us a lot of heartache if the content in the Schedule tab had changed to red to warn us that there was nothing actually playing.
This is a scenario where I'm not sure if a default playlist would have taken over or not, since we did not have one set up for that player. Since the PLAYLIST was not expired, but the ASSETS were, would it have reverted to the default playlist? If not, it should. Otherwise we end up with a blank screen.