Quote:
Originally Posted by
ferbal 
PROBLEM:
From the 200 hours, my AE2000 had developed a persistent and visible lack of color uniformity. The problem was observed as a cyan color stripe in bright white picture and dark red stripe in a black image. It covered almost the whole width of the bottom of the screen, with a height of approximately 4 (10 cm).
Referencing a post from 6 months ago: I just want to note that I'm another person who had this same "sticky ribbon" problem. My projector only had 22 hours on it but (for various reasons) went unused for about a year with plastic around it to keep the dust out. When I powered it up in January there was a big blotch across the picture, visible as green on a black screen and magenta on a white screen. There were also slightly visible horizontal distortion lines around and below the blotch area. Test patterns confirmed the problem was in the green light path. A white frame looked something like this:
Unlike ferbal's description, my blotch was actually a substantial distance up from the bottom of the frame, so at first I assumed it was dust or some other blockage instead. Attempts to spray air into the green path did nothing to help.
Thanks to the pictures and writeup, and because my warranty was up, I decided to dig deeper into the projector before calling Panasonic. As soon as I pulled out the polarizer assembly the problem was blatantly obvious and was exactly the same as ferbal's: the phase difference board (a little clear panel) had come loose and slid downward in its little metal frame. The edge of the panel, which has a ribbon of adhesive on it, was now within the light path. The only reason my blotch was higher up in the picture was because the projector had been sitting longer and the part had been able to fall farther out of alignment.
I tried simply pushing the panel back into place to see if it would stick. I left the projector disassembled overnight, and within 24 hours it had already come loose and fallen again. I considered using some additional adhesive, but I wasn't sure how hot this part of the light path gets and didn't want to risk anything flammable in there. So instead I made a little metal clamp. For material I took an excess slat from an aluminum window blind and removed the paint from it with sandpaper. I cut it with scissors and bent it into shape with tweezers, attaching it by simply bending little tabs around some notches in the existing frame. I'll admit it took several attempts to get it right, but in the end I managed to get one attached that was just the right size and shape to do the job. It should both hold the "loose" edge of the panel against the frame, and keep it from sliding downward even if its adhesive gives out.
The original sliding had caused some adhesive to get smeared onto the normally visible portion of the panel. I used isopropyl alcohol and cotton swabs to carefully clean it.
Note that I never had to actually detach the phase difference board's frame from the rest of the polarizer assembly. Using tweezers and a small vise to hold things steady, I was able to do all of this in-place. It was a little awkward at times but it meant I didn't have to worry about marking its position and realigning it when screwing it back on.
Everything's been reassembled for a month and so far the projector is working perfectly again under regular use. Even with test patterns I don't see any distortions or non-uniformity in the image. Thanks to ferbal for posting about it in the first place. For anyone else who gets the same problem and is out of warranty, this does seem to be something you can fix yourself if you're careful.
