I have 3 Pelco PTZ cameras installed on a project and they are continuously going down. The video is still recording but you cannot use the PTZ. It seems as though the cameras are constantly losing comms with the joystick. I am told the the back box door assembly keeps going bad on the cameras but from everything else I hear these things rarely, if ever, fail. They are installed in a tent structure with metal frames. The cameras are mounted on the frames and the tent is grounded. The cameras are not. There is some heat associated with the cameras. We recorded about 130 degrees the other day on one with a laser thermometer. Could it be some kind of static discharge? So far in the past two months we have had all cameras repaired and 2 replaced for a total of 6 swap outs. Any ideas?