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Discussion Starter #1
Several models of DLP projectors have been reported to suffer a build up of contamination on their color wheels. I'd like to conduce a poll to gather some more information about the timing of this phenomenon. Currently, we believe this is due to outgassing of volatiles which are then deposited upon the color wheel. It may have another explanation(s). Fortunately, the contaminant appears to be removable with some careful effort, but I believe most people (and manufacturers) will prefer that their projector color wheel be cleaned at a service center while under warranty.


If you can remove the bulb of your projector and shine a light at the color wheel, please look and indicate what you see in this poll and the accompanying bulb reflector poll http://www.avsforum.com/avs-vb/showt...7#post3584627. The color wheel should look like clean colored glass. If a film of contaminant is present, it will look foggy or milky. You won't be able to see through it clearly.


>>>>If you vote that your projector has developed a visible contamination film, please also post your projector make and model in this thread. Also indicate if anyone smokes in your home so we can establish this is/isn't external smoke.
 

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Discussion Starter #2
NEC HT1000 at 827 hours - Contamination film was severe. No smokers
 

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Nec HT1000 @ ~1050 hours -severe

no smokinig

Temp 68-75 Humidit 40%

house filtered ~1.5 micron

dog
 

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Discussion Starter #7
bump.


Is the wheel still exposed to something else which can outgas inside the sealed volume? We don't know. "Sealed optics" isn't a rigorously defined in meaning. Even the HT1000 has "sealed optics" but the color wheel is not sealed from the bulb chamber.
 

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Again I think this is unscientific since I only happened to check the colorwheel contamination when my colors could not be calibrated sometime around 1160 hours.
 

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Discussion Starter #10
Agreed, this is a very rough survey of the problem. We can't get the time of when it first shows up because people don't regulary inspect their machines every few hundred hours. I hope we can at least shine some indirect light on the problem.
 

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NEC HT1000 with only 200 hours: color wheel has some uneven contamination. (I voted in the 400-499 category because it was the lowest to choose from.)


No smoking.


-- Peter
 

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NEC HT1000


Have around 400 hours on bulb.

My color wheel looks like Guy's but only lighter amount of milky covering.


I also have almost the exact same crazing as Guy in the picture he posted.


And no one smokes in this house. Never has.
 

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HT1000 @ about 330 hours. Just some dust blobs on color wheel (and inside sealed optics since new), but no contamination film yet.
 

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Davis DL450 >4000 hours no contamination... However dust / dirt / etc WAS present though, a simple alcohol clean sorted it...
 

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At 650 hours no colorwheel contamination noticed. I cleaned anyway and the Qtip showed no sign of dust or anything. I cleaned with distilled water. My filter did show a small amount of dust as it had at 250 (LOTS of dust then) and 450 hours (very little dust).

PJ is an X1.


After viewing this poll I wonder if some of the contamination is there when we bought our PJs?


I do not smoke. No smoking is allowed anywhere in the house.
 

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Discussion Starter #16
If you vote yes, could you also indicate in the posting whether or not you smoke. Please go back and edit your responses if you already posted.
 

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Discussion Starter #18
If you assume that once a machine's color wheel is contaminated it will continue to remain contaminated, you can add the number of affected machines at lower hours to the ones at higher hours. Divide that by the number of votes and you get an interesting plot of affect machines vs running time. The curve looks like a straight line that points back to 200 hours. Like the reflector deterioation, this process seems to be one which linearly worsens with time. It does seem to begin at a later time.
 

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Guy,


I think it is very important that there is a bimodal distribution of results in terms of a problem or no problem. If one assumes that those with no problems will continue to have no problems it could mean that there is a batch of lamps that was made improperly. This could be the root cause of both the reflector problem and the film=perhaps a different plastic source for example for the housing.


It would be interesting to find out if the material that is used in the HT1100 is the same or different and if different if the reflector and/or film problems are observed.



Just a thought.



Joel
 
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