The "lamp" would actually be a CCFL lamp behind the panel, and they typically don't go out, and it's not a user-replaceable part. Unfortunately, the only recommendation I can make is to see if switching to "Dynamic" settings would help. If not, you may want to consider having your unit serviced.
My 2 year old LCD TV has lost its bright crisp picture......it seems dim and not as defined. I tried to adjust using menu options but nothing.....does my tv have a "bulb" that needs replaced and could it be bad already?