Okay, here's a quick guide I copied from the manual.
So we're narrowing it down to a couple of possibilities. It could be the lamp, or it could be the fan. If you can hear the fan, it's likely going to be your lamp.
Here's a Samsung_HD_Tech quick fix, and I'm throwing it out there because I've done this numerous times in my line of work, and more times than not, it works.
I'll walk you through a process that will "Re-seat your lamp". If you locate and open up the lamp housing, you'll see your lamp.
Here's an example of what you'll see:
Now, if you either unscrew the two screws where the yellow arrows are, or the one screw where the red arrow is (Depending on the model you have), you'll be able to pull the lamp out a little. Don't worry, the screws shouldn't fall in the unit, as they should be attached to the lamp housing.
You don't have to pull the lamp all the way out (if you do, that's okay), but if you pull it out a little (6 inches or so), and then <b>firmly</b> push it back into place and rescrew it in, and close up your outer panel, that may very well fix your problem.
The outside panel does need to be back in for the television to turn on. There is a blue kill switch there, but you don't want to fool with that.
A few general rules here.
1. If you do pull the lamp all the way out, do not touch the glass face.
2. Perform this procedure while the lamp is cool, and preferably not after consecutively watching Star Wars Episode 1-6.
3. If the first one doesn't take, try re-seating it again. It may take a few times to reset whatever is triggering the warning.
If it doesn't work, and you need a new lamp, you're already a pro at knowing how to install it. But I do think that if your brightness levels are acceptable, that a simple reseat may very well fix your problem and give you more time on that lamp.
So a recap: Unscrew the lamp, pull it out a little, firmly push it back in, rescrew the lamp, and close it up and see what happens. It sounds crazy, but if it fixes your problem without a service tech OR a new lamp, that'd be a good thing.
Keep me posted!