I think i'm having the same problem - I have a Samsung LCD TV ( LE46A558P3FXXU ). It is out of warranty.
About 3 months ago, upon switching it on, the whole screen would come on normally apart from 3inches on the left hand side - which would stay dark, then after a minute or so would flicker into life (like it needed a minute to warm up - a bit like when you turn on strip lighting).
There's an image under the dark patch, but if the image moves or changes it leaves a residual image behind for a few seconds, creating a blur.
It annoyed me a bit, but after a minute or so the dark side of the screen would wink into life and i'd have a normal picture for as long as the tv was left on.
Over the 3 months it has progressively got worse - it would take like 15minutes to light up.
Now it basically stays dark all the time.
I found this clip on youtube: http://www.youtube.com/watch?v=jJF2wmNZZ78
which is pretty much what mine looks like, but on the left hand side of the screen.
It's definately not the same problem as the 'power on problem' that's discussed in the other thread though.
Anyone had any joy with this problem? The youtube page had some comments suggesting it was from 'three ribbon cables that make their connection in that area. you can go in and try to reseat all three connectors behind the foil sheilding tape' - but i don't know what that means!