AVS Forum banner

Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
283 Posts
Discussion Starter #1
Okay, here's my problem. I followed the instructions found here to dislodge dust particles off my X1's DLP chip with compressed CO2 (didn't want to chance using regular compressed air)... but it wasn't strong enough and irony of ironies, I got a drop of condensation on the chip anyway, so I had to do a direct cleaning with a lens tissue and lens cleaner. I used Ultra Clarity which contains Isopropanol and is what Zeiss uses/markets for their antireflection coatings.


I did a thorough cleaning of all the lens elements and mirrors in the projector and it came out really well, except for the fact that after running the projector for a few minutes (i.e. added heat), a rainbow-like, oil-slick discoloration manifested itself at the lower left of the projected image and also at the bottom center.


Do I just keep cleaning with this lens cleaner until I get a distortion free image, or should I switch to denatured alcohol (ethanol), distilled water or some other solution? Anyone here have similar issues/advice?
 

·
Registered
Joined
·
889 Posts
I'll offer my opinion for what it's worth. I'm of the opinion that the DMD should "never" be touched and unfortunately you have ruined your DMD.I was told that a non co2 air blast was the closest I should venture to it.
 

·
Registered
Joined
·
83 Posts
I used one of these (see pic), I don´t know the name in english (cotton stick maybe). I remove the lens, and gently clean the chip. Firts I pass it wet with only water and then dry. Result=perfect. No dust and no damage to the chip.
 

·
Premium Member
Joined
·
301 Posts
I have used Pec Pads and Eclipse cleaning fluid to clean the sensor on my Canon DSLR. I imagine that it would work well for the optics or your projector
 

·
Registered
Joined
·
889 Posts
Cleaning the optics is one thing, scrubbing the DMD chip of a projector is quite another. I cant believe this would be reccomended by anyone who owns a pj they expect to work after.
 

·
Registered
Joined
·
61 Posts
Best chemical IS NO CHEMICAL !

If DMD/MIRROR/OPTICS need cleaning, suggest microfibre optical cleaning cloth, these are availible from optomistrist(can't spell), eye glass people.

DMD is not so much the problem, its the reflective mirror which is surface coated with silver oxide, very fragile optically.
 

·
Premium Member
Joined
·
2,247 Posts
Noah recalls correctly, there is protective glass directly in front of the DMD, of course you'll want to remove this and give those little mirrors a good scrubbing. Just kidding do not touch the panel, I've been using Kodak lens cleaner and mircrofiber cloth or Q-tips depending on the accessibility of the surface I wish to clean. I understand the Kodak cleaner is fairly mild but still cuts through grease.
 

·
Registered
Joined
·
1,094 Posts
This is tricky, something comparable happend to me and it took me half a dozens trials at least to get rid of it. The good news however is this smear will take care of it self if you arrange things in the proper way. Try the following before you do anything else:


1. Project a black screen, place a piece of paper infront of the lens and get yourself a perfect overview about the range and amount of contamination on the DMD cover.

2. Still projecting a black screen (to rise temperature in the optical engine as much as possible, don't be afraid, the X1 can handle this quite well) let the projector run for 24 hours if possible.

3. Check again with the paper. The contaminated area should be smaller now or gone.

4. If there is still something repeat.


In my experience these smears due to condensat on the DMD cover tend to evaporate completely. Those little rests of condensat I never was able to get rid of manually went away using a similar approach as outlined above. Otherwise after100 hours of normal usage it should be gone as well.
 

·
Registered
Joined
·
283 Posts
Discussion Starter #11
Thank you all for your advice. It's much appreciated. I have a microfiber cloth that I can use instead of lens tissue. I just need to clean it first. I will consider using some of the other cleaners and possibly cotton swabs mentioned above. First, I think I'll follow the advice of drpp, and see what that does.

drpp, I came across your post from earlier this year:

Quote:
As I said above some time ago, the X1 DMD can be cleaned 'wet' is everything else fails. I did this with very pleasing results. I used the opening where the lens is seated. I had to build a 'swap' from clenex and a pencil, soaked it with a small amount of concentrated isopropyl-alcohol and was able to clean the DMD cover completely. The procedure is not for the lighthearted, as one has to remove all traces of the isopropyl. It took me several approaches to do this. Condensed breath to wet the DMD evenly with destilled water worked best. I used the (meanwhile dry) swap to give the cover a final touch. For the first time since my first dustblob, the X1 DMD is totally dustfree. The paper-test reveals a complete black rectangle, without any 'stars'.
I'll follow your welcome, new advice and see if it does the trick, otherwise my warranty is still in effect, and if all else fails I'll just get it fixed. I noticed last night as I was directly re-examing the surface of the DMD chip, that the dispersion-like distortion almost appears similar to a small amount of liquid between two microscope slides... as I applied the lens tissue with varying degrees of slight pressure, it seemed to change shape over time. This is odd, since I was very careful to not use too much lens fluid and didn't wipe the entire glass plate that protects the DMD... just the area in front of the active silver mirrors.


The distortion is not noticeable on a black screen... the opposite is true, it is most noticeable on a white screen (I'll provide a picture if you want) -- though I understand why you want me to use a black screen for heat. I just want to confirm that this is the same problem you had. It's exactly what you would expect if an oily liquid were trapped between two pieces of glass at the image plane, causing a rainbow, oil slick-like dispersion of colors in a wavy pattern.


Thank you again.
 

·
Registered
Joined
·
1,232 Posts
Yes, the PB6200 has a shielded DMD as well. I believe all DMDs are sealed, otherwise a dust mote could cause serious problems if it lodged in the mirrors.
 

·
Registered
Joined
·
889 Posts
Why has everyone always said to never attempt to go near the DMD? I've seen literally hundreds of cleaning threads and never till now do I hear this?
 

·
Registered
Joined
·
283 Posts
Discussion Starter #15
I just wanted to say thank you, Peter, for your advice!


I ran the projector for eight hours (rather than 24 straight) per your instructions. I noticed somewhat of a change in the bigger multicolored dispersion/blob. Then just last night, I watched two movies back to back and the bigger blob was completely gone! It may have had something to do with my anamorphic lens being right up against the projector lens, completely sealing off that silver, plastic semicircular area around the projector's optics for both movies, perhaps raising the temperature inside a bit more. The micromirrors being in constant motion may have also played a role in raising the chip temperature.


So, after 12 hours of non-continuous operation, there is still a slight discoloration in the left bottom corner, but it is hardly noticeable. I will report back if that disappears as well. But so far so good. And of course, no dust blobs against black! Which was the initial reason why I attempted this in the first place.


Because I didn't take a picture of the initial problem I had, here is a Photoshop recreation of what it looked like against a white background:

http://home.earthlink.net/~particlew...een/before.jpg



And after:

http://home.earthlink.net/~particlew...reen/after.jpg
 

·
Premium Member
Joined
·
2,247 Posts
That's awesome, a great tip from Peter.
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top