Hello folks- A customer complained about a "cloud" on his 52" RPTV. I checked the TV and saw that he indeed has what looks like grey dirt, which looks like a cloud. This dirt is visible only on bright scenes. I cleaned the screen and the lenses (outside only) without success. Can dirt inside one of the lenses cause this ? Or, is it possible dirt somehow found its way inside between the fresnel and the outside screen ? Or maybe his cleaning habits did permanent damage to the lenticular screen ? One thing is for sure: the "cloud" is there. I'm trying to avoid any unnecessary disassembly. Thanks for your opinions.