Toshiba Rear-Pro problem

[Wiggins]

I've owned a Toshiba 56WH08B for several years now. It doesn't get a lot of use- usually only a few hours at weekends to watch dvd movies on.
I have a toshiba dvd player connected via component inputs.
Just recently I have noticed black static lines running left to right across the screen. Usually this is only evident on brighter images i.e. skies etc. But I think I can see it a lot now. Does anyone know what this is?
I'm starting to think it is burned into the screen as I can see it when you bring up the menu with a blue screen background. If it is an image burned into the screen- what is the solution? Is it likely to be a fault with the tubes?
Any help/ advice would be appreciated. I've called Toshiba, but they told me as I was out of warranty I would have to call an engineer- and the nearest one for me is 20 miles away.
Cheers
Wiggins