For those of you out there with LCD projectors that are getting along in age and are starting to show color uniformity issues this thread might help you out! I totally psyched about my results.
I've owned my Panasonic L300U (same as AE300) for about 2.5 years now and use it a fair bit. On a recent check I was at 2536 hours of my first bulb. This projector (knock on wood) should last until 5000 hours. Over the years I've developed a few dust blobs and have opened my projector once to clean them out with partial success.
Well, within the last year or so I started to develop a bad color uniformity problem seemingly overnight. It wasn't as bad as the picture shows below, I think that is partly a trick of the camera to saturate the pink tint more than it really is. However, it was bad and did get worse over time. Of course, me being an AVSer, I noticed it right off and it really kept me from enjoying the movies on occasion (bright, uniform scenes in particularly snow, sky, etc). No one else really noticed or at least they didn't care enough to comment.
Here is a picture from before the surgery the projector is just showing an all medium grey image. Again, I purposely shot it so the pink would show up, it's not that bad in real life... but it does suck:
So, what is the problem It must be those dreaded blue polarizers right? I've read the TI white paper, I know LCD sucks and has a short lifetime
I assumed I was screwed and just lived with it for the last year or so just waiting for the day I could afford a nice LCOS or 3-chip DLP (I'm bothered by rainbows). Then I cam across this thread: http://www.avsforum.com/avs-vb/showthread.php?t=559557
Post #10 in particular was intriguing to me as they said they cleaned off the polarlizer and the pinkish tint went away! Hmmm I called the Panasonic repair shop to see what I was up against. If they cleaned it out for me, it would be a minimum $100 labor, plus $30 return shipping, plus shipping it to them (maybe $25?). If the polarizer was bad, I would have to pay to replace it (another $100). So I was looking at minimum $155, maxwho knows. I decided to give it a try doing a deep clean myself, if I screwed things up I could always send it in anyway
So I took it down from the ceiling mount and opened it according to these instructions (in the quote box): http://www.hometheaterforum.com/htfo...51#post2248651
I didn't take the whole thing apart but I did undo the ribbon cables coming from the LCD imagers, as well as taking off the PCB board on top of the optical block. After a thorough de-dusting, I went in for the polarizers. First the blue
My first thought was, THIS COSTS $100!!!! It's just a little piece of plastic. Anyway, I checked it in the light
It seemed ok hmmm Oh well, I dusted it off anyway. On to the green polarizer
DING, DING, DING!!!! Clearly this was the problem. There was actual dust built up right on the polarizer! I always figured the dust would be on the LCDs.
It's clearly in the same pattern as the red tint on the screen too. Well I dusted it off thoroughly. The red checked out ok. Same as the blue. So I finished blowing the dust out and put it all back together. When I remounted it and turned it on this is what I saw. I included a before and after so you can get the full effect!
YEAH! The moral of my story is if you have an LCD projector, and you have crappy color uniformity it might indeed be the dreaded blue polarizer or it might just be some dust! Open it up, blow it out, good as new. If you don't have an Lx00u, you should still be able to find a service manual online or buy one from ebay. Enjoy.
P.S. I take no responsibility for anyone breaking their projector trying to dust off their polarizers... proceed at your own risk