Hello all I'm a complete noob at this stuff so forgive me if my question seems trivial. We have a CCTV system that was here when we bought. Now a couple of the cameras do not work. The wiring would be quite involved to replace so I'd like to just replace the cameras but I don't know what to buy. Pictured is the board from one of the cameras. That board screws into a dome and one simple three wire white plug is plugged into it and the dome twists into the base screwed into the ceiling. That's it but looking online there are so many different types I have no idea what to get. Any help would be greatly appreciated.