Lighter gray smudge marks on blacks with IN76 - No Dust blobs

Ok. I bought an IN76 awhile back that had 9 hours on the lamp but a badly messed up image on the left side like. It's hard to explain really. Almost like dust blobs that badly effect even bright scenes and made things blurry and foggy.


I got it for $430 shipped figuring it was dust blobs and would be an easy fix. So, I took it apart and noticed it was something on the glass in front of the DMD. At first I thought the glass was cracked. I tried to wipe it with a q-tip, but nothing. So, I took a butter knife and scraped the are. Something started flaking off. After that I got a great image.


However, there is still a lot of lighter spots and excess light spill around the 16:9 image noticeable on a fade to black or low contrast dark scenes.


What causes this? It's like smears on the glass. Is the anti reflection coating rubbed off in spots or something?