No video signal?

1. check if equipment power supply is normal or not.

 2. check if the receiver corresponding channel video indicator is on or not 

A: if the indicator is ON (the indicator ON show this channel has video signal output). Then Check the cable connecting between receiver to monitor or DVR and other terminal equipment is ok or not, video interface connection is loose or has a cold solder joint etc.

B: video indicator of the receiver is not bright , check if the front-end corresponding channel video indicator is ON or not. (suggest the CCTV receiver power up again to ensure synchronization of the video signal)

a: the indicator is ON (means video signal camera captured is sent to the front end optical multiplexer), check whether the cable is link or not, Optical port of the optical multiplexer and cable terminal box is loose or not. suggest re-plug fiber optic interface (such as pigtails head is too dirty ,suggest use alcohol cotton to clean until dry and then insert).

 b: Indicator is not bright, check the camera is working properly or not, and the video cable between camera and front end transmitter is link reliable or not. Video interface if loose or not ,and if there is any cold solder joint and so on. 

If the above method does not exclude the fault and have the same type of CCTV multiplexer, can be used to replace inspection method (requires device is interchangeable),that is, fiber link to the other end of the receiver which work properly or replace the remote end of the transmitter, it can accurately judge faulty equipment.

CCTV Multiplexer: