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DLP Projector Problem (HP SB21)

3174 Views 4 Replies 4 Participants Last post by  superchazrock
I have an Hewlett-Packard SP21 DLP projector, and I am running into a very strange issue that I would really appreciate some help on. When hooked up to my laptop, the display looks perfect except for one thing- half of the screen is dimmed out. You can still read the dimmed out portion of the screen, but it isn't anywhere near as bright as the correctly function half. The border between the dim side of the screen and the well lit part is curved, and there seems to be a sort of prism effect going on between the two sides (you can see a sort of rainbow right where the two sides meet).

My thoughts are that maybe the bulb was somehow knocked out of alignment which is disrupting the path of the light through the lens, but I have no experience with projectors so that's only a guess. Any help at all would be appreciated.

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Have you pulled out the bulb-housing to have a look see?
It could be misaligned mirrors in the optical chamber. I doubt it's the bulb as it's either on fully, dimmed, or off. You can't have just 1/2 screen brightness. If there is an iris which I doubt as this is a budget business PJ (SVGA, I do believe), the iris could be out of alignment as well. Lastly, it could be part of the lens assembly that's out of alignment. Was this a "travel" PJ or one stationary, dedicated to HT? Sounds like warranty repair or self-repair (open up and see).
I haven't had a chance to look around inside yet, but I'll do that as soon as I get a chance and let you know what I find. This is definitely a travel projector, with the entire company dragging it out to meetings and presentations, etc..., so it wouldn't surprise me if, like you've suggested, one of the mirrors has been knocked out of alignment. Thanks so much for your help... I was out of options since the warranty period has run out.
I've had the same problem for a few months now (BenQMP720P), and I just found out it happened to my brother too...

I replaced the bulb (had a bulb replacement warranty plan, and the bulb needed replacement anyway), hoping that would fix the problem, but it didn't. My roommate and I both looked inside, but neither of us saw anything that LOOKED out of the ordinary.

My brother said that he took his apart, cleaned the color wheel, and put it back together; when he put it down, it still wasn't fixed, but then he put it down hard and it was miraculously fixed. Obviously this method isn't recommended, but there must be something jostled inside.

I'm planning on taking it apart and inspecting more closely in about a week or so, but for now I've gotta work on some stuff for school...
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