What are the signs/symtoms of a rear projection LCD tv bulb going out?

My lcd tv is a 46%26quot; rear projection LCD about 4 years old. Any time the screen shows black such as changing inputs or watching a movie when the picture is black there is a faded spot in the center of the screen about 12%26quot; in diameter. The faded spot is not black(or blue since it is a LCD) and is lighter in color than the rest of the screenWhat are the signs/symtoms of a rear projection LCD tv bulb going out?Usually the only difference is the picture will be dimmer than it should be, but unless you have a new bulb to try you probably won't be able to tell. The symptom you stated is not a problem with the lamp/bulb. I am not sure what it is but it's not the lamp.
What are the signs/symtoms of a rear projection LCD tv bulb going out?
You have to go to the store where you bought it from and ask them signs of the bulb going out.