I have read about this problem before and the only fix I have read that is said to work is, go into the picture options section in your Samsung menu and set size to just scan. This is said to work. Hope this helps.
I have a ln40a550 which i sometimes use as an external display to view my movies from my laptop. I have a dvi to hdmi cable to connect my laptop to the tv and i just noticed today that my tv no longer fills up with my desktop background. ive tried reconnecting the cables and redetecting the external display but no matter what i do, there's still a black border all around the screen (both horizontally and vertically). what do i do to get it back to the way it was before because now when I view movies widescreen doesnt work because of the vertical borders in effect, if that makes any sense at all.

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