cam dropping from nvr

Hey all, Bit of strange one, about 3 days 3 of my cameras started going black, flashing picture and showing text of version and video out. It eventually stopped the following morning but last night all 8 cameras started doing the same thing. I ve restarted the DVR and unplugged the power to...

Hello, I have had non stop problems from the beginning with my NVR allowing 11 x 8mp 4K cameras to connect and record contentiously for a period of time, usually upto 5 days of working fine, and then one or two cameras all of sudden will show no video within there square on the monitor and...