good evening ; I wanted to ask you a question I am changing the dvr equipment that was installed in the home of a family member, the previous one I had, I had a video fault. I installed it the same way the other was; place the sata hard drive; I passed it from the old team to the new one. Then connect the 4 UTP connectors that are from the 4 cameras Then connect the dvr to the rj45 cable to the router (do not finish the configuration on the Internet at the request of my relative, as it should look the same for a monitor connected directly by vga) Connect the monitor by vga. and finally connect the power source 12 v. the dvr starts working normally; He asks me to do all the default settings; And at the end ; the 4 grids are seen; of the four cameras simply in black and with the manufacturer's logo (in this case MARK) on and nothing more * I verified that the cameras have energy; and I found the particularity that I wanted to consult I looked at the wiring and I have 4 UTP cables and one red; that red wire is connected to a 12v power source on its positive side; independently; to dvr connection I will try to prove the last source I mention; but I wanted to consult this detail of why nothing is seen on the screen since everything is connected as it was and how it worked on the other dvr; Moreover, we buy an equal dvr of the h.264 class I would greatly appreciate your help

I don't quite understand what you mean by the "red wire" ... The cameras apart from using a pair of the UTP with the balunes (one +, for example green and the other - for example a pair of green) also need power with 12 V. You have to see from the previous installation how those cameras were fed, surely that "red cable" that is part of the UTP was to take the 12 V to the cameras. If that red cable is bipolar, surely a cable was for the + of the 12 V and another for the - of the 12 V. If it is unipolar, perhaps the positive of the 12 V source was carried by that cable and for the negative one I used a cable that was left over from the UTP. You should better specify the issue of food because almost certainly therein lies your problem. Regards.

There are DVRs that emit POE (power over ethernet) and others that do not. Check if the cameras get power because maybe the new DVR does not have it and the cameras have to be powered by external source

What you have is a difference from norna. You have to change the dvr or the cameras. Luck