Major flickering on a number of cameras

[uatuba 0]

I have installed a 16 channel DVR with 15 of the basic Zmodo cameras. On a number, there are major flickering and horizontal line problems. The reason I say "a number" instead of giving the exact count is that the problem is not consistent by channel. I can unplug/replug the AC adapter into the BNC cable and the channel may start displaying the picture clearly.

 

Thinking that the problem may be interference from fluorescent lights, I ordered shielded Cat5e and some baluns. I made sure all of the cable was at least two feet from all of those fixtures, hooked everything up, and it still made no difference. I have swapped out the cameras, the cables, and tested the channels on the DVR with multiple cameras (all of the channels are working). It seems like a power issue, but I have no idea what the issue may be. Does anyone have any ideas?

 

Thanks!

[shockwave199 0]

How do you have all those power adapters distributed- in power strips? If you're maxing out six way channel strips, you could try using one more strip so each one isn't full and redistribute the adapters around to see if they all get happy. Oddly enough that worked for me in the very beginning when I had a similar flickering problem, but I didn't have horizontal roll though. I think I may have also swapped out a couple power adapters too- the ones that come with cameras are usually really poor and can be hit and miss. Are your cable runs very long? Also flickering can happen when the available light changes drastically, back and forth throughout the day. If it's seriously dark and cloudy at times, a couple of my cameras in shady areas will flicker a bit until they settle in. It always clears and they always work properly at night- being IR cameras. Are your cameras TDN and do they have menu items to tweak, or is everything auto with no menu in the cameras?

[uatuba 0]

Thanks for the tips. There are two power adapters for the 16 cameras. Each is split into 8 ends. The cable runs are not very long (60' is the longest, 10' is the shortest and that run has this problem as well). I have tried plugging in just one camera, for example, and the problem doesn't resolve. If this were a ground loop issue, what would I do to resolve it?

[shockwave199 0]

I don't like split adapters. And they are made to be full up. I really wouldn't have anything less than eight cameras in them long term. But you might try and get separate adapters and see if it helps. Most would recommend a quality power box rather than a lot of adapters. Certainly that's a good idea, but depending on the quality of your cameras it could just perpetuate a ground loop issue anyway. As much of a drag as separate power adapters may be, I just prefer it. You could find the slim type so they all fit nicely in power strips. And you could try maybe four of them to start and see if that helps those four cameras. If it does, it may be the way to go. Good luck.

[YourManLynch 0]

if its giving like a rolling affect across the screen it could be ground loop. The PSU might also not be providing enough power to the camera or if you wired it with Catv and baluns, make sure its a good connection cause it will pick up cross talk or interference. Personally I prefer the baluns where you screw down the terminal rather than the push in ones.