Did you ever get this sorted?
... eek! That sounds like it's done some damage (not ITV 3 and Midsomer bleedin' Murders is it?!!!)... you're right about the built in screen burn thing, I've always found it dubious as to how it works... I'm guessing all the 'put it on a different coloured screen' jazz is... er, just jazz?Nope, was meaning to post about it but never got around to it.
Really lost tbh as on board tool on TV left on for the whole day and yet didnt reduce or remove the burn in at all.
Problem is my parents watch one channel mainly and that channels bloody logos is burnt in the top left and bottom right corners of the screen
I've got a tool where it alters the brightness and dark levels to keep it in check.
What's the make and model of your TV?