Debris on projected image

[[email protected]]

First time posting on this site. Iv had this Benq 1070w projector for 8 years now. Its always been great, i recently had to swap out a fan on it and ever since i did ive had these smudges that show uo during dark scenes. Upon closer inspection i can tell im seeing debris if i adjust the focus. Where would this debris be and how do i get rid of it. Ive cleaned the outer lens glass, the colourwheel and the lamp housing glass. Has anyone had this happen to them before?(image 1 shows the debris after adjusting the focus, image 2 shows the smudges im seeing during dark scenes.)(fyi i have the projector set up temporarily while im trying to fix it. Thats why the image isnt centered on the screen.)

 

[Kapkirk]

I'm no expert on projectors but this definitely looks like dirt/debris on the lens (inner/outer whatever) had the same thing happen to one of my SLR cameras and no amount of cleaning helped, in the end I got it professionally cleaned which cured it.

 

[[email protected]]

I'm no expert on projectors but this definitely looks like dirt/debris on the lens (inner/outer whatever) had the same thing happen to one of my SLR cameras and no amount of cleaning helped, in the end I got it professionally cleaned which cured it.

Thanks for the quick reply, yeah worst case scenario that might be what i have to do. Im hoping somone has some insight as to how id get inside to clean it out. Ive taken apart as much as im comfortable with so far. Gunna go try some compressed air now, maybe itll make a difference.

 

[[email protected]]

Went at it with the compressor the best i could and it didnt help much.

 

[jfinnie]

If you unfocus the lens image and it snaps into sharp focus it is usually on top of the DMD device itself, which means removal of the lens assembly usually to access. I've done it on a much cheaper BENQ before, was a pain in the rear, but do-able.
These videos might help - different projectors but the principles will probably be similar.

 

[Spigot]

Since you can bring the debris into focus then it's definitely on the glass surface of the dmd chip. The range of focus isn't big enough to focus on any of the lenses that are cm's away from the surface of the dmd.

Here's a video of someone inspecting a dmd in a 1070 (at 16seconds). He's changing the thermal paste on the heat sink that clamps to the back of the dmd: