For awhile my infocus X10 would get an effect where the color gradients would come out in bands (I think they call it posterization). Just recently it started flickering on the left hand side of the screen, and I fixed it, so I thought I would share what I did...
At first I tried just opening it up (as other have described above), and cleaning the black duct and metal screens with compressed air, vacuum, and/or alcohol wipes. I also added a fan to pull air away from the color wheel. When I got it all put back together, and on the ceiling. The problems had gotten much worse. Now it only took about 5 minutes for poterization to start. A few minutes after that the screen would start flickering, but now instead of just the left side, it was the whole screen. Also, a new problem occurred, the projector started switching colors. In other words, it would be all red for less than a second, and then all blue, and then all green. It was very psychedelic. When I got close to the projector, I could hear a ticking sound. My guess is this was probably the color wheel sticking, which was causing the crazy color effect.
I figured I had probably destroyed something in the projector beyond repair, but I thought I would give it one more attempt. This time I opened the projector back up, and I also took off the metal plate (which I hadn't done on the first attempt). I sprayed compressed air everywhere I could. I also made sure to spray around the color wheel, and the small fan near the color wheel. When spraying any fans I could see, I made sure to hold their blades, so they wouldn't spin.
I then put the projector back together, and turned it on. When turning it on, I realized something...:The fan on my X10 doesn't suck air in through metal vents on the side and push air out through the vents on the bottom. Instead, it pulls air in through the bottom vents and pushes air out through the side vent. I think this makes sense, as the lamp probably heats the air the most, and it is the last thing the air travels over. Thus, when I put a fan above the color wheel that sucks air out, this fan could pull air from the hot lamp to the color wheel, and actually make the problem at the color wheel worse.
Here is a pic to show the airflow:
Thus, I turned off the projector before it heat back up. I added the external computer fan back to the air holes below the color wheel, but this time I had the air push into the color wheel instead of push out. I also added some foam weather stripping around the fan to keep the air going into the vents below the color wheel (or above if you are on the ceiling). I had to use something as a spacer, because my ceiling mount was partially in the way, and I couldn't put the fan directly on the vents. Here is a picture of it mounted on the ceiling:
This fixed it. I put the projector back on the ceiling, and have had it running for 2 hours with no posterization or flickering. It seems either the reversal of the external fan I added, or the cleaning around the color wheel made the biggest difference. (I didn't test without the fan.)
This brings me to a question. Why are the metal filters on the side there? I thought originally they were to keep dust out, but as the air flow comes out of these screens, instead of going into them, they act instead as dust traps. They actually just keep dust in. (Maybe they dampen fan noise?) I'm thinking next time I need to get in there to clean, I'll just remove these screens entirely. Is this a bad idea?