Good question, I recall someone saying that the complete optical path was sealed. I'd call tech support, whatever you do, don't smack it, to try to dislodge it, especially if it's still hot.
You can try changing the background to one of the solid colors, I think if I remember right, it had green. Then from the side try to observe if there's something on the lens (there will be reflections from the light that look odd), but never look directly into it while it's on. If the light path is not sealed, canned air can be used to blow it out, but only when the unit is completely cooled off.