Blue circle


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DLPFan
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Blue circle

Postby DLPFan » Mon Mar 16, 2009 7:44 pm

Hi,
I recently purchased a Phillips P22 100/120W 1.0 Bare Lamp for my Hitachi 62VS69A LCD Projection TV on 2/20/09. Saturday March 14th a circle appeared in the center of the screen. It is a 36 inch circle and color is blue. The corners of the screen area are darker.
What could be the problem?

ovadoggvo
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Re: Blue circle

Postby ovadoggvo » Tue Mar 17, 2009 12:39 am

DLPFan,
It seems like your LCD light engine's color prisms are starting to deteriorate due to the heat of the lamp. The lamp is not the issue as this is a common problem on these LCD Projection TVs after 4-5 years. Unfortunately the optical block is the part that needs replacing and it is expensive. I would check with Discount-Merchant.com to see if they have it in stock as they seem to sell them at around $250 to $350. This will save you lots of money!

Look at this post, it seems to have a good explanation of how an LCD Projection TV works:

viewtopic.php?f=18&t=56


It's unfortunate because those particular sets have a beautiful picture that to this date can fairly compete with today's plasma and LCD sets! Good luck..

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Eddie
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Re: Blue circle

Postby Eddie » Thu Mar 19, 2009 9:52 pm

--

Eddie

Rivers85
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Re: Blue circle

Postby Rivers85 » Tue Aug 04, 2009 5:25 pm



The light engine for the LCD rear projection television works with three LCD color chips (red, green and blue). Inside the light engine, the light passes through several mirrors and filters which separate the light beam into three beams of light redirecting them to pass through each one of the color chips. Then the three rays of light reach a prism which sends out picture to the screen.

Here you'll see the schematic of the LCD light engine: http://www.oerlikon.com/ecomaXL/index.p ... _projector

Through time the heat of the light beam will start to ware off the chips until they get burn marks causing colored blobs in the screen.


LCD Color Chips.JPG
LCD Color Chips.JPG (34.66 KiB) Viewed 5408 times



Damaged Color chip.jpg
Damaged Color chip.jpg (6.67 KiB) Viewed 5408 times



Yellow Blob.jpg
Yellow Blob.jpg (44.09 KiB) Viewed 5408 times


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