Hi 'Peterlem'. Firstly let me say I know absolutely nothing about
the Beo 9, but offer my sympathy if something serious has happened.
But, reading about the TV, I read this:-
"After
every 120 hours of TV use, a little sensor arm rotates out from the
center of the bezel at the top. The screen displays a graduated gray scale test pattern. The sensor measures the color temperature
of the white and black points and compares it to the factory
calibration. If there is a difference, the TV is adjusted automagically.
During the process, the screen blinks to black a few times."
Could the screen have blinked to black during the above process and
stayed like that? Sorry if this is a silly idea, as I said I don't know
anything about this set.
Good luck though.