I got this for free from FB market, the previous owners said the monitor started bugging out and eventually stopped working. Been reading the forum and trying everything and jumped on this thread because buddy seems to be having similar issues as mine. The only difference that I see is that the usblinx pcb doesnt have any lights turning on.I still think you either have the settings incorrect, monitor needs adjustment, or a combination of both.
Take a picture of:
-back of the monitor chassis
-the monitor plug with the signal wires
-the monitor controller board (in your coin door)