Samsung HCL4715w has a dim picture

I have a Samsung HCL 4715w that is about 5 years old. Over the weekend the picture got dim all of a sudden. It looks faded. And it has a slight intermitent  flicker. Last night the picture was dim  and then all of a sudden brightened up to a normal level for about 10 minutes and then got dim again. The colors appear right but faded and the picture is not blurry. Any help would be greatly appreciated