Viewsonic PJD7820HD Dust buildup behind lens

[Stan Ziberna]

My projector seems to have collected dust within the projector itself. I have read on several forums that this unit does not have filters and can accumulate dust behind the lens.

Has anyone noticed this and tried to clean it?

[Stan Ziberna]

Also, has anyone noticed this causing any issues with print quality?

[Stan Ziberna]

Ok, I think I am starting to rethink my dust hypothesis.

What started with a couple of dots that I happened to notice a few days ago is now looking for like a star field.

Starting to get worried. Thoughts?

[mUVe 3D Admin]

Stan,

It's possible to clean but can be difficult to manage so please use caution if you proceed. Sometimes you'll just end up getting more dust in there than what you started with.

Since you're seeing this problem you'll probably want to start looking at your work area first. What is the large source of dust and what can you do to make sure the projector isn't sucking it in. Typically there needs to be a direct source, or a very dusty environment for this to start to happen. Or if you go too long between cleanings and accidentally blow dust into the unit when trying to clean it.

At the end of the day the spots might not do too much, it'll just depend on how bright they become. If you start noticing print artifacts then you'll have to get in there and clean things up as well as you can. Do this in a very clean environment and maybe take the time to watch a couple bulb replacement videos online. The areas you need to clean are all placed right next to the bulb, so that'll need to come out first.

mUVe 3D Support

[Stan Ziberna]

At this point I have ruled out the entire dust idea.  The environment I am operating in is not at all dusty. 

It looks like the DLP chip is breaking down. The other day I noticed an extreme increase in the amount of white artifacts appearing on the screen.  The projector was off for a three hour period from one power on to another and I have seen an extreme increase of artifacts.

This is causing many types of different artifacts from dots to small lines that remain bright white.

[Stan Ziberna]

I am also suspecting that another indication from the start may be the fact that my cure times are 26 seconds compared to 9 to 12 that have been seen from others. 

[mUVe 3D Admin]

Stan,

If there are dots outside the projectable area, ie the outline box that you have in the images, then it's dust. Pixels going bad don't cause ghosting or bright spots outside the projectable area. They generally fail pretty hard too, a couple pixels is unlikely. So based on what you've shown us so far it's definitely not chip failure but dust in the light path.

If you're seeing further degradation then the chip might be on the way out, but without a few more images it's hard to tell. Can you show us more of what you're experiencing?

One thing worth noting too, from your images it looks like the image might be out of focus. While it might be a difficult image to shoot, we can't really tell if that could be the reason for increased cure times, or something else. If you can get a sharper image we might be able to tell what's going on a bit better.

mUVe 3D Support

[Elliot McAllister]

Hi Stan,

I have found that the Viewsonic outter lens is separable from the projector.  

It's mostly plastic body with a metal spring clip....unscrew at the users risk.  But I got mine off by twisting hard with a little torque off axis...

[Elliot McAllister]

Hi Stan -  Also want to add that a small smudge (if you took it apart and didn't get the rear optic extremely clean) can cause this too...again experience!  Ha.  IPA 91% after windex and then a glass cleaning cloth takes care of it.

E