hello guys i had a customer call me wanting me to help with the security cameras. i dont know much about them and mostly cleaned lens and did some adjustments, focus, and replace a connector. anyway some of them dont work. they run on coax cable with a second cable for power. when i unplugged one of the cams two that werent working came up. when i reinstalled the cam the other two went off again. i traded it with another cam and it still cut off the other two. anyone know what would cause this. they seem to run to a computer of some type. not sure of the brand. thanks dave