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12 Posts
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23575
November 8th, 2004 01:00
3300mp spots in dark scenes
I've noticed numerous lighter spots of varied size during dark scenes with my
3300mp projector. They are diffuse and usually not noticed by others unless I
point them out. If I take a piece of paper and hold it about 10 inches from the
lens the spots come into focus and look like stars speckled all over the image.
At this distance the image is out of focus of course. If I look into the lens
at an angle, I can see all these stars in the back on what looks like a mirror.
Does this sound like a lamp abnormality or what? I have 450 hours on the lamp.
joden1942
3300mp projector. They are diffuse and usually not noticed by others unless I
point them out. If I take a piece of paper and hold it about 10 inches from the
lens the spots come into focus and look like stars speckled all over the image.
At this distance the image is out of focus of course. If I look into the lens
at an angle, I can see all these stars in the back on what looks like a mirror.
Does this sound like a lamp abnormality or what? I have 450 hours on the lamp.
joden1942
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sonisame
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73 Posts
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November 8th, 2004 14:00
Hi
I have noticed same things on my dell 3300MP projector that I bought 3 or so months ago. My lamps has only 160 hours on it. I heard that it was dust particles behind the lens, and cannot be cleaned.
Cheers
joden1942
12 Posts
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December 19th, 2004 02:00
Thanks for the reply. I know it's been awhile, but I had one heck of a month.
Some health issues, but they are fixed now.
Anyway, I was not happy to hear that the dust problem is supposed to be something
we have to live with. I think dell should address this problem better.
I reasoned that if the dust can get in there, it can be removed. I tried just
blowing through the vents on the side without any results to speak of. I also
tried some canned air, but not much changed. I did notice a slight improvment,
but not enough to satisfy me. Then I decided to get out the big gun. I have an
air compressor. I took a chance and blew higher pressure air through the vents,
and this did make a difference. At this point the spots are less numerous.
the vents have a screening on the inside, so I think the higher air pressure got in better. If you try this, be sure your air is dry.
good luck,
dennis
joden1942
Ken Goldberg
22 Posts
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December 19th, 2004 13:00
These are not necessarily dust particles - I think they are more likely "stuck" mirrors from the DLP chip. If they were dust particles, they would likely not be seen in black scenes, as there would be no light going through the lens to show them, if you catch my drift.
DLP works by having a whole lot of mirrors that flip open (light) and closed (no light), synchronized to the color wheel. Sometimes the mirrors get stuck in the "open" position, so that light is always reflected through, and will appear "white" on the screen. There are also likely mirrors that become stuck in the closed position, but you'll never see them (no signal on a dark image, and they will be drowned out by their brighter neighbors in a bright image).
This is analogous to "stuck pixels" in an LCD screen. You will see (slightly) more of these over time. Dell's policy does not state replacement terms for these specifically. I have them too - we all will in time. My personal approach is that if my friends don't notice them, I'm going to leave them alone. When they become very noticable, as I purchased an extended warranty, I'll make a stink.
Comments from Dell?
joden1942
12 Posts
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December 20th, 2004 14:00
are round for the most part and some are several inches in diameter. These do not
show up as solid white spots, but translucent discs against the dark backround.
When I blow air into the projector they change. My projector is ceiling mounted
in a basement room which is not overly dusty, but no home is without some dust.
I have an air cleaner running at all times in the room. If you look close at the
screen when the Dell logo is on you can see the tiny squares which are made by the
mirrors. As I said in my original posting, if you take a plain sheet of paper and
hold it close to the lens these spots come into focus. I also think that being only
about 13 feet from the screen does not allow these spots to spread out and diffuse
more. As it is now I am living with it and have improved it by blowing it out. I don't
notice it unless I look for it. It's like when you lose a filling in a tooth, you
can't keep your toungue away from it. When it comes time to replace the lamp, I may
have a better look at it.
joden1942
TrashyRabbit
11 Posts
0
January 15th, 2005 11:00
Wattsnxt
2 Posts
0
April 17th, 2012 09:00
You are correct, it is a defective DLP chip. What is Dell's policy on warranty of their DLP equipment? I have a Dell 1209s with a defective DLP chip although the unit is out of warranty I was curious if they still covered the DLP chip? Mitsubishi and Infocus exchange their units out up to 5 years if the DLP chip is defective.
Thanks
Frank H
barjohn
5 Posts
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September 10th, 2012 21:00
Once a unit is out of warranty Dell does nothing but send you to their rip off service company that wants $250 just for shipping and diagnosing the problem. Then you pay for parts at what will probably be an inflated price since you can't buy the parts anywhere. Additionally, even if you give them the symptoms they can't tell you what the parts are likely to be and cost unless you spend the $250 first. Thus, you don't know whether you will face a $400 to $500 service bill until you commit $250. The question is do you want to risk it when you can buy a new projector for $500 to $600 that will often be better than the one you are trying to fix. I think they should either offer a flat rate fix, or a minimal ship it to them and review and estimate for less than $100.