I had been getting some intermittent noise from my Panasonic PT-AE900E video projector after some years of usage. It sounded like a dry bearing on a fan, but it turned out that it was iris that caused the problem. I decided to take a more look at this problems when I had time to change the projector lamp.
Panasonic PT-AE900U noise solved discussion gave a clear description of the problem:
I finally found that the iris was making the noise. It opened and closed smoothly but was making a low grunting sound that you could feel through the iris structure. I turned the projector off, put a single drop of 3-in-1 type machine oil on the pivot point and worked it in my opening and closing the iris by hand. I buttoned it up and figured that I would have to replace the iris or disable it in the menu.
PT-AE900 Question discussion also said:
One small drop of oil on the two bearings and the mechanism turned much faster. I took the lamp out and cleaned the optics when I already had the covers off. And now I have noticable better picture and the grinding sound is gone!
A later post in this Panasonic PT-AE900U noise solved discussion points to this How to fix projector PT AX100 E / U with WD40 and cotton tip 1(Now with long term fix) that shows how to fix that problem in another Panasonic projector, but the instructions also apply well to PT-AE900E projector because the iris construction look the same.
I have to agree with those instructions. This seemed help to solve the problem on PT-AE900E projector as well. There has been different recommendations on the best oil to use on different forums. I ended up using KONTAFLON 85 PTFE based dry lubricant (based on teflon lubricant recommendation). It seemed to work well at least on first tests. The projector became considerably less noisy, although all the noise is not yet gone on all occasions.
After few days of testing at some of the noise came back, but the projector is still less noisy than it used to be. So the question is still should I add more oil to the same place (maybe some other oil type)? Or should I look for if there is another pivot shaft to oil also ? Or just accept the noise level I have now.
For other information on servicing this projector can be found at The Panasonic PT-AE900U service manual, and how to fix a noisy projector web page. There seems to be the full projector service manual on-line.