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Discussion Starter · #1 ·
So I replaced the bulb in my Optoma HD70 after about 2000 hours of use, HUGE DIFFERENCE. It's like new again, except for those darn dust blobs.


I disassembled the whole projector (far out of warranty, as I've had it over 3 years), and cleaned the light mirrors and the color wheel. I can't seem to find where this dust is or where it got lodged, but I'm out of ideas.


I followed the guide here:

http://tantht.blogspot.com/2009/02/h...om-optoma.html


I event went a step further and removed the board and cleaned the color wheel front and back.


It seems to have made the blob worse and even add another one.


I don't mind taking it apart again, but I figure I'll have to dump at least another $150 into it to get it cleaned. I only have 1 or 2 hours on this lamp, I would rather return it if possible and just pick up a newer 1080p model if I am going to be $400-500 into an old setup.


Does anyone have suggestions?


Here, you can see both of them, the obvious one on the right.


Thanks


 

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I had dust blobs on a NEC dlp projector and cleaned all the lenses and mirrors to no effect. Then I saw that I could actually focus on the dust blob and resolve it into a dust fibre. This led me to believe that the dust must be very close to the DMD chip since that's where all the lenses are focused. Sure enough, when I used a blower brush on the DMD chip the problem was solved.


Now, I could only see white halo's on a black image, whereas yours appears to be the exact opposite. However, if you can twist the focus to its limits and actually focus on the offending bits then the problem should still be on the surface of the DMD chip.
 

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Discussion Starter · #3 ·
Thanks mabuk, any idea where this DMD chip is located?


Edit: Actually, I opened the dust cover to the optics chamber and cleaned the DMD with a q tip. Unless the dust is behind it, it appears fairly clean.
 

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Discussion Starter · #4 ·
Took it completely apart, including the DMD board and chip. I pulled the chip out and cleaned it, re-assembled everything and the blobs are gone.

 

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Congratulations on fixing your problem!


(NB I had the problem on a NEC HT1000, and fortunately all I had to do was remove a couple of covers and I had direct access to the glass surface of the DMD chip. The Optoma sounds like a more complex beast.)
 
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