I still use analog cameras for some customers and recently experienced something I haven't experienced before. I got a call that one of the cameras wasn't working at one of my client's locations. The location is about 4 years old. The cameras are powered by AC24V Altronix power supply. There are 6 Nuvico IR Easyview domes with an older Nuvico DVR. The camera that went out had been displaying only black and white and had stopped displaying color images before finally not showing any video. I went to check the power supply and all connections. Everything checked out so I changed the camera. I turned off the power supply and changed the camera. When I powered the supply back on, only 2 out of 6 cameras came back on. The new one was one of the 2 that came back on. I messed with the power supply and a third camera came on.
Today, I changed the three cameras that weren't working and installed a different power supply and UPS. When I powered everything back on, the third camera that had come back on by luck, didn't come back on and is now bad as well.
The same setup is in another store across from this one owned by the same person with pretty much the same setup but has not had any issues like this. The stores are both in a mall. The 2nd store cameras do not have IR and were existing from the previous tenant and were simply repositioned to keep costs down.
The cameras are receiving power inside the dome, but do not output video. The cameras are supposed to be dual voltage but the original cameras that were working would only work on 24VAC and no longer powered via a 12VDC supply. The newer camera powered up with 24VAC and 12VDC.