I was given a hand down, Samsung PLK435WS Rear Projection LCD. I was told that the "bulb" is brand new, but when I turn the TV on with my my cable box hooked up, the picture is very dark and the colors are way off. It looks like there's a bright spot on the TV (right in the middle) that seems to dim the rest of the display. It's very hard to make out lettering and the picture is more vivid and bright on my 20 inch CRT... is there anything I can do to fix this problem? Clean the lamps? Anything at all?