Hi everyone, I thought going cheap might have problems, however, we bought 4 cameras and NVR from ''ali'' , after connecting, one not working at all ,and a couple days later second one failed. Probably fairly basic, but is it necessary to turn off the NVR when connecting or disconnecting cameras.? LED on camera plug not lighting, have tried connecting to other ports, changing cables etc, nothing works. I'm new to security cameras, and forums, so any help appreciated, thanks.
