We have three (presumably) identical sony STB's attached to three
separate TV's all driven by boosted signals from a labgear dist amp.

Last night ONE, and only ONE was giving either 'no audio/video or a red
screen announcing that yes, you had BBC4, but it wasn't actually on.

The other two were showing the Copenhagen film.

All showed 100% signal level and quality.

By going into the manual tune section, I was able to pull BBC4 up on
channel 39..


I selected it, and then on exiting the menu, but not before, finally
normal service was resumed.

I cannot for the life of me puzzle this one out...anyone got any ideas?