I have a QSee 8 camera system that has been installed for more than two years and operating 24 x 7. Several of the cameras are beginning to get out of focus. Since they are all fixed focus cameras, it is the CCD's that are getting tired? And if so, is it possible to replace them? I googled looking for maybe a youtube video showing the process but didn't find one nor did I find anyone selling replacement CCD's.
Sometimes even on fixed focus cameras you can twist the lens either right or left to adjust far or near focus. I would suggest trying this. Also if the cameras are facing into the sun the Iris can be damaged.