Home security system - one camera wierd problems at night

Roger Davis

Distinguished
Jul 6, 2012
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18,510
I have a very weird problem with one of my BNC wired cameras.


This camera is in an 8 camera system. I have two transformers supplying camera power, and have switched power supply plugs several times, trying both transformers and several separate wires. Local line voltage is a steady 119.


I've been very careful to make sure all connections are clean and good, especially the coax ground to the camera and DVR which didn't quite seem secure at first.


The other 7 cameras work well, no matter which power supply or power connection is used.


I can switch the camera connection on the DVR, the problem follows the cable and camera, not the display location.


The picture on the problem camera is bright, clear, and consistent as long as there is any light outside. Once there is no daylight outside, the picture is noticeably darker than the other cameras.


At random times, the already low brightness will fluctuate, becoming noticeably darker, then recovering, then slightly darker, etc.


Also, usually before, after, or during this time, there may or may not be very short duration horizontal lines on the picture. The lines don’t seem to move, just appear and disappear.


At some times when the picture is darkest, there may also appear very black lines horizontally across the picture. These may be pretty thin (maybe just a few percent of the picture height), or very thick (like about ⅓ to ½ the picture height).


Maybe one of 10 times the darkness, lines, etc. appear, the camera will disappear to the system, showing the same indications as if there is no camera connected. This may last from a few seconds to maybe an hour or two. Then the camera will just reappear by itself, looking like it did just after dark.


All these problems may or may not appear multiple times through the night. Next day all is fine - until night arrives again.

This situation is not easy to just swap out the components (cable and / or camera) to isolate the problem as both are very difficult to reach. I’m hoping that someone here with lots of experience can use that experience to help me nail the problem down.

Thanks!
 

Ralston18

Titan
Moderator
Can you correlate with temperature? At some temperature the connections are good but with cooling/contraction become loose/intermittent?

Can you see the cables along the way and use some extension pole (non-metal of course) to gently wiggle wires and connectors while someone is watching the picture. Use cell phones to coordinate....

At night is it possible to shine a light on the problem camera - see how it responds. I.e., brightens perhaps but still shows interference/static lines.

Just brainstorming a bit in lieu of being able swap out cameras.....
 

Roger Davis

Distinguished
Jul 6, 2012
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18,510
1) It doesn't seem to correlate with temperature. As night approaches, but the camera is still on color setting, all is good. As soon as it switches to night (infrared) it's possible for the problem to begin. The temperature had no time to change, but with infrared operation, current requirement will (I think ?) increase, as well as switching to different internal camera systems ?
2) About 10 ft of cable are in an easy to reach place, and I have wiggled those. about 25 ft are in a difficult to reach cavity. Another 25 ft or so are high up outside. I might could reach the outside run and wiggle that. I'll try that and report back. That will take a few days.
3) I've tried the "shine the flashlight" trick, no long term change, but I had no one watching the display. I'll try that too. Again, a few days

I'll try to conduct these tests when I've got the black screen instead of just the interference.

One thing I did try that seemed to temporarily correct the situation - I have a 15v power supply (12v is normal) that I plugged in and quickly unplugged one time when it was black. The display came back, and the infrared seemed VERY bright. I guessed that was over driving the camera, so quickly unplugged it and reconnected the standard power supply. The display was back for a while.

This is a Q-see system if that helps.

Thanks!