I have a china manufactured, wired, video doorbell system installed which has worked well since I installed it several years ago. The bell, video and door unlock systems stopped working recently but the audio still works, from the camera end anyway. I am looking for a typical circuit design for both the camera and monitor to help me troubleshoot the system. there does not seem to be an industry color code for the six wire cable connecting the two units

 

. I am looking for a typical circuit design for both the camera and monitor to help me troubleshoot the system

Hello there
I hope this helps.