[bugman72]

As some may know, I have been having some problems with streaking on my Viewsonic PJL830 (Davis DL450 Clone). I decided tonight to take it apart to see if cleaning would help the situation out. As I was looking around inside, I noticed the square prism-esque piece that goes from the color wheel into the area where the DMD is.


Here's the deal...at the end closest to the color wheel, I can see a fan-shaped nick out of it on the bottom side. It looks as though the piece might have been put in wrong (I don't know for sure) as there is a notch in the piece that I would assume would go on the bottom, to straddle the metal base. Does anyone know what I am talking about? I don't have a digital camera at home, but will get one so I can try and get a picture of this.


Could this be what is causing the streaking I am experiencing (see photo of problem)? And, if so, is this piece replaceable or do I need to buy a complete light engine?

 

[JoeFloyd]

That's not a prism. It's part of the optical engine that takes the light from the lamp and tries to make the light rays more parallel and also make the intensity of the light uniform. This is important for making the final image have acceptable contrast and acceptable uniformity. It's one of the more important components in the optical engine for a DLP projector, so if it has a defect you have a problem.


It's unlikely that the projector left the factory with this defect, but it could be caused by thermal stress or mechanical shock.

 

[bugman72]

I called Viewsonic Tech Support last night to try and see if I can purchase just the glass rod and not the entire optical engine. In a nutshell, no one could even talk to me about the internals of these machines. I was transferred to Parts and they said that since Davis went out of business, they are trying to find a supplier of parts for these machines. I still don't have an answer as to whether I can purchase just the glass rod.


I went ahead and cleaned the projector while I had it apart. Got everything back together and it DID improve my PQ a bit. Didn't help the streaking problem at all.


I tried to take some pictures of the chip and the notch that is cut out of the rod, but my digital camera will not take a good picture that close.


Does anyone have any ideas as to where I can obtain this piece?

 

[JoeFloyd]

Sometimes projectors on E-Bay are sold for parts. You might try keeping an eye on the auctions just in case your model of projector is one of those.