Channels 1-4 suddenly not working

I have an 8 camera system H.264 DVR, ZMD-DD-SAN8. I think I have had it for about 3 years and never had any issues, then suddenly I have no signal on my cameras 1-4, 5-8 are working fine. I thought maybe the cameras just died so I bought a replacement camera and plugged it up and no power either. Is my DVR going out?

Did you try to rescan all channels? Im not sure if this is possible as this an older model but perhaps you can try. Are you able to restart and see if it works?
Let us know

I’m not sure what you mean by rescan? and yes I power cycled the DVR a few times with no sucess.

On certain NVRs, there’s an option were it allows you to scan for your cameras. Perhaps the option is not available on older NVRS.

try powering one of the cameras directly it could be you splitter that went out or the power supply. Every set of 4 cameras should have a power supply