The cable run is 60 ft. The power comes from a transformer at the DVR end, so 60 ft for that too. I'm using one of the larger diameter cables, not the really skinny type.
I can't easily swap out cameras, I prefer to take a shot at either cable or camera and get one. I could pull one of the other cameras and swap it in there, but it's a difficult to reach location, and switching really multiplies the work, since these cameras are REALLY difficult to aim and this is a difficult place to get to. I may end up doing this, though.
Another new detail - I have a 15v power supply (std is 12 v) at hand, and tried this at one time when the screen was black. The camera came back on line with a VERY bright picture, very bright infrared illumination - so bright I guess I was overdriving the camera, so I immediately unplugged it and went back to the 12V. The camera went back to working the way it was. This was only a one time thing, though I plan to try it again on the next long lasting black screen. Does this provide any more clues?
Thanks!