Thanks Videobruce! I checked the previous posts.
With all hopes (since all other parts I cleaned - inspired by this forum , did not help to fix the issue) Finally, decided to open the metalic plate. The mirror on the otherside of this metalic plate looks special! In my case, I did not find any rsidual film/haze/dust inside. After fixing the part back, TV did not loose any focus or sharpness (Fortunately) of the image projection.
My original problem is not resolved by this procedure
I still see 'lighted' screen even when there is no picture coming from source. Again - hard to explain but some picture I am attaching here may give you an idea... strictly speaking - the legendary Mitsubishi DLP TV is not producing 'black' level reliably at all. only those scenes which are mix of good light and dark shaded look good. As soon as 'low' light or dark scenes start, even my other family members notice the difference.
I now suspect it may not be mirror/lens/dust/haze. It may be the DMD chip (?) itself? But again only time DMD chip replacement is needed when you get - permanent white/black dots on your screen right ? My problem doesn't look like the same. There is some light coming on the screen like a 'noisy' (analogue TV) picture all the time.
Any suggestions ? or pointer ?
Mirror on the back of the metalic plate.
My DLP TV's - weird - loss of black levels issue:
Illumination of screen when actually it is supposed to be full blank - dark!
Only enjoyable scenes like this :