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This post gives a little info about how to repair an LCD projector that has a washed-out and yellowing image, which results from the blue LCD panel weakening over time.  I would have to guess that at least 30% of the used projectors on eBay have this annoying problem!

I bought a reconditioned Proxima 9260+ projector three years ago, and it has served me well with a wonderful bright, colorful, and high-contrast image.  I've probably used it a total of 800 hours now, and it has been great.  Liking the unit so much, I bought two more of the same kind for really cheap in an eBay auction.  I figured if they were lame then at least I would have parts.  But if they worked OK then it would be an amazingly great deal.  They were advertised as functional, but in need of a lamp replacement.  When they arrived I found out why they were so cheap: one didn't have a lamp at all, and with a good lamp installed both delivered a really poor washed-out image, yellowed in the middle.  Content on the sides of the screen looked marginally OK.  At the time I was kinda disappointed thinking that perhaps someone had run the units with a really dirty filter, making the inside hot, and roasting the LCD panels.  What was strange though is that both units had about the same hours on them, and both were affected in just about the exact same way.  Didn't seem likely that two projectors could have been ruined in the exact same way unless it was a manufacturing defect or something.

So this evening I dug in to figure out the problem because I've got a pretty big event coming up in two weeks, and I really wanted to get one of my two crappy units prepared as a back-up projector in case my nice one dies during the event.  So I took some time to experiment and see what I could come up with.

Inside an LCD projector there are mirrors that separate out the red, green, and blue components of light, delivering each color to a specific LCD panel.  Then these three panels sorround a prism that combines red, green, and blue from the panels back together to create the resulting image.  After opening the nicer of my two beater units I turned it on and tested each color by shielding the path of the LCDs in sequence.  From this I found that the blue channel was the problem.  It showed detail on the outer edges of the image where there had been less light intensity over time, but in the middle the blue channel didn't respond at all to a signal, and always let about 30% light through.  Black parts of the image look washed out with a bluish tinge, and parts that should be white turned out yellowish from only getting 30% of the blue channel.  These white areas basically were getting 100% of the red and green, and then blue at about 30%.  This combines to give a yellowish result.  With the projector open and running, I covered up the blue channel, and the red and green portions of the image looked clear and accurate, and blacks were again black.  So I was confident that the problem was either with the blue LCD panel or its polarizer.

Fortunately the LCD panels used in all 3 channels on my projector are exactly the same, with the same ribbon connector and everything.  So I cannibalized a working LCD panel from the green channel on what then became a donor projector, the lamer of my two beater projectors.  After installing it I had to do lots of fine-tuning to get the blue channel in focus and lined up perfectly with the red and green.  Annoying, but I eventually got it close enough to look OK.  All this alignment had to be done with the projector running, loosening and tightening four allen screws that hold in the panel, and nudging it around.  I had made and was projecting a simple cross-hatch pattern in Paint to let me line everything up right.

After dusting out the unit a little and bolting everything back together, it provided a nice, contrasty, colorful image just like my other pristine unit.  I'm delighted with the results.

Curious about why the blue channel was the one that had worn out in both units, I searched on the 'net a little and found that LCD panels naturally break down in the presence of strong ultraviolet light.  The blue channel from a metal halide bulb happens to deliver tons of ultraviolet, so this is a very common problem with older LCD projectors.  Three years ago TI, the inventor of DLP technology, conducted a study to see if projectors using LCD panels wore down over time.  They used the smallest projectors on the market, with little LCD panels only 0.7 and 0.9 inches diagonal.  These would break down sooner under the same amount of ultraviolet than the larger 1.3" or 1.8" panels found in larger conference room type projectors.  Their findings were that the blue LCD panel will always wear down a noticeable amount by 3000 hours of usage, causing that annoying yellowish image.  My units have the 1.3“ panels, which will hopefully last a little longer before throwing in the towel.

Another thing that can happen in a projector is to get blurry magenta spots.  This just means that dust has gotten on the LCD panels, and it can be cleaned out with compressed air.  (Careful to do this only when the unit is off and cold since canned air will cool the panels down quite a bit, and if they're hot to start with then they could crack.)

Anyway, for anyone else with a Proxima model (really made by Sanyo, and built using Sony LCD panels) it's fairly straightforward to replace if you have a long 2mm Allen wrench on-hand, and lots of patience when you go to align the image.  Five screws to take off the top cover, and some delicate work with the ribbon cable and LCD panel swap-out.

Maybe my next trick will be to try and refurbish the lamp like some of those other guys out on eBay are doing.  Osram manufactures some good replacement lamps for cheap that would fit the bill.  I think it will be awhile though before I get enough free time to try that out!

Posted on Thursday, August 24, 2006 12:49 AM | Back to top


Comments on this post: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I am curious but I heard of people using car headlights as bulbs for there projectors.

I dont know if this holds any validity or not but hey just figured I'd pass it along.

Car headlights seem like they would run quite hot to me maybe I'm wrong...

I myself would love to try an array of leds being as the light from a led is more focused and the hours on leds are amazing.
Left by hmmm... on Jun 28, 2007 9:11 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I have a projector that when turned on the whole screen is light pink. Different from the dust spots you described. The whole screen is light pink with what ever image is being projected.
any help

please email me
jpwebb@yahoo.com
Left by jpwebb@yahoo.com on Nov 20, 2007 2:27 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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What is the solution to the pink color problem. An Infocus Proj. LP 850 in my office has the same pink color problem.

Will appreciate a reply.
Left by Floyd Ragsdale on Jun 11, 2008 4:18 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I have a Phillips LCD projector that has a greenish tint on the bottom its the greenest and gets better up to the top.
Is this repairable, if I know what the cause was and were to get the parts I'm sure I could fix it.
Left by Justin on Jul 31, 2008 2:35 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Excellent story! Now I know why my Hitachi CP-X328 suddenly started to develop a blue distortion on one side of the image. But anyhow, I need to replace the whole damn projector.
Left by Gee71 on Oct 28, 2008 10:42 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Great information. I think I am the lucky one to get a dead-column, flickering LCD panel. It is giving me the creeps. I've exchanged it with the green panel and moved the problem to the green color -- until dechanged. I wonder if I would ever find another panel to that proxima ultralight LX pj...
Left by Avenger on Nov 03, 2008 2:57 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I am thankful for this valuable information about Blue LCD panel Going BAD.In my Experience I had come across several projectors with this kind of defect,but i never suspected the ultravoilet light to be responsible for causing the Blue LCD Panel to break down.
Thanks Lot.
Left by Saad on Jan 11, 2009 7:47 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Anyone know where these LCD panels can be purchased on line please.

JB
Left by John B on Jan 13, 2009 8:39 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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i need help i have CANON LV S3 and i need the blue lcd polarizer... where can i purchased one...help me...
Left by jonas on Mar 25, 2009 1:22 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I have the same problem on a proxima 5900, can I buy a LCD from you as they are the same and I am having trouble finding a donor
Left by Kevo on Jun 22, 2009 1:49 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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I have a Sanyo LCD that's 10 years old. I have a shadow of the 3 colors to the left of the image. Would this be a problem with alignment?
Left by JoeP on Jul 24, 2009 7:47 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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i've (3) HITACHI_CP-X325W , the picture become about (70% yellow) on it in the middle of the screen ?
what is the reason . and how can i solve?
v. thanks
adel
Left by adel on Oct 21, 2009 3:54 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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i had aprojector with gost i mageses i needed sam one to help me
Left by sekamanje samuel on Oct 27, 2009 2:49 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Thank you!d f
Left by DDos Protection on Nov 06, 2009 11:30 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Wow some people are well dense... The article above describes how the yellow tint is caused - so if you have another colour tint then it isn't rocket science to surmise that perhaps it was another LCD panel that's gone bad. If it's pink, then perhaps the green panel is bad? You can use complimentary colours to work it out. Or do what I did and open it up to have a look. However - I would only recommend this if you are proficient at a) building PCs etc or fixing TVs, and b) handling cameras or optics and have a basic understanding of how these projectors work.

The Panels are identical - the model numbers aren't different - the serial numbers are. The top line is generally the model number. Some sites in China sell them - but you need to be able to read Chinese! If anyone has any luck buying them directly from China let us know!
Left by RoganGunn on Dec 17, 2009 1:59 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Good input on this subject I am a tv engineer and came to the same conclusion.

Also check the blue polorizer filters on the three colours before changing the lcds,a dead giveaway of a failing lcd is do you have to turn one of the RGB settings higher than the others to make a good grey scale ie (black & white picture with the coulour fully down)
Left by Clive on Jan 01, 2010 7:35 AM

# if anyones out there... i've found a good replacement for a halide lamp.
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i recently bought a used projector off ebay for the grand sum of £12.50(with postage - the projector itself was 99p:-). it had no bulb, the front of the case was smashed off, but when i put a 50w halogen in it, it worked perfctly. i bought a 20w led from china (look on ebay...) and found this could produce nearly the same amount of light as the origonal bulb, and was focused enough to light the lcds properly. i have tested the projector with the led and found it to produce a sharp, bright, iamge. i am planning on building a linier power supple for the projector that runs from 20vdc (the same voltage as the led ballest) so i will have a projector that runs from somewhere between 30 and 40 watts! anyway (christ this post is long!) there cheap, take very little power, and dont produce any ultraviolet light.
Left by markthesmall on Jan 09, 2010 1:03 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Hi I have a 3m x75 ..just out of warranty of course. and getting blue blob growing down left side of screen, I'm tool this is the first stage of a dying lcd .. I have another same unit under warranty that keeps blowing bulbs I 'd like to switch the lcd's before I send in .. Is this doable for a rookie can any one help or provide a step by step I'm in ont Canada
Left by Perry on Feb 17, 2010 3:15 PM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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encountered this in two distinct infocus lp850 (or equivalent) projectors. on one the image was incredibly blue and blurry. perhaps this means 2 lcd's are going, both green and red?

anyone have success in buying new lcd's? or polarizers?
Left by daniel on May 19, 2010 12:06 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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Some things are better off junked and starting with a fresh machine.
Left by chegg on May 31, 2010 3:17 AM

# re: How to fix an LCD projector with a washed-out yellowish image (blue LCD gone bad)
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LCD Proyektor tempat saya bekerja baru dinyalakan 5 menit sudah mati dengan keadaan lampu indikator temp.merah yg bertanda bahwa temperatur terlalu panas padahal tidak panas dan terus seperti itu LCD ini jarang sekali dipakai,bahkan terkadang baru muncul ceek sinyal tiba2 mati nanti diam sebentar hidup lagi kalo lampu inikator temp. sudh tidak berwarna merah lag.beli 1 tahun yang lalu dipake tidak mesti 1 bulan sekali,mau menggaransikan tidak bisa karena ini dulu adalah bantuan dari lembaga lain,kira-kira ini masalahnya apa ya?Merek VIEW SONIC.
Left by OBENG on Jul 29, 2010 8:01 PM

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