# Projector Polarizer going bad?



## NickVon (Oct 5, 2009)

I've done my google research and spoke to an IT person on campus though his diagnosis i couldn't find any thing on the interwebs to back it up.

Our projector is an older model Panasonic PTL6500U Been here for three years at least.

When displaying white or grey backgrounds (like PP, or Excel) a noticeable discoloration can be see some of the edges. (in our case, the Entire top, Entire Right, and a blotch against the side along the bottom) It yes yellowish and gives a bit of an unwanted burned paper look. 

The little I was able to find out seems that it might be the organic compound on the "blue" polarizer (because it's yellow.) Campus IT said it could be the "CCD" chip though i couldn't find any reference to this on the internet.

Our projector does seem 'wise" enough to have been using the organic polarizer vs the newer method that uses Inorganic substances for the job.

Any thoughts or experiences with this from others.
I think i'll have to end up finding a time soon when it won't be needed (as it's used every week) and actually take it to repair shop and have them tell me that it'll cost 3 grand to fix it. :-( But thats me being negative, maybe it'll be 75 Bucks .

After i resolve this, i have another question regarding out Professional rental Venues and other college theatres mange the "lamp hours" of their installed projectors with faculty meetings, lectures, club events, etc that use their spaces?

Thanks in advance folks


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## JohnHartman (Oct 5, 2009)

My first question is how old is the lamp in the projector?

and have you put in a new lamps to see if the problem is with your lamps and not the prism or filters.

I have seen similar problems as you describe due to old lamps or mis-matched lamp pairs.


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## NickVon (Oct 6, 2009)

They are essentially brand new lamps by lamp standards. There where new and installed last April, and projector sees very limited used from may through September. Last lamp pair went for an easy 3 years, (since i've been here)


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## SHARYNF (Oct 6, 2009)

it MIGHT be some sort of crud/mold or what ever growing on the color filters. Sometimes when these sit around for awhile and are in a space that might not have the best humidity control or ??? you can get some build up on these. It MIGHT be possible to have them cleaned. Be prepared for the before we can test it we need to replace the lamp story, get all the time. 
Sharyn


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## ruinexplorer (Oct 6, 2009)

Yes, it is possible that you have burn through in your polarizers. Depending on your use, many LCD projectors can have burn through in as little as 1000 hours (generally speaking much more than this). Most people won't notice burn through until over 2000 hours. However, with burn through the dicoloration is generally more towards the center. Instead of that, you may some optics out of alignment internally. I am not familiar with Panasonic LCD projectors, but with the Sanyo (Eiki, Christie models included), it was fairly easy to correct for this misalignment if you have a maintenance manual.


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## JohnHartman (Oct 7, 2009)

Well with relatively new lamps it sounds like an alignment issue in the optic chain. It is possible that there is something "growing" inside, however unlikely. Sounds like it was bumped around hard enough to goof up the works.


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