1. Check whether the channel switching of the matrix is correct or whether the control instruction is sent correctly.
2. Check whether the current output resolution and refresh rate is supported for the display device. Since some older models of the resolution supported by the display device may be lower, you need to set the mixed matrix corresponding to the resolution of the output interface for display device and the corresponding resolution, such as 1024 ×768 or try to modify other resolution and refresh rate.
3. Check whether the input and output signal lines of the matrix signal board card and the connector plug are connected normally.
4. Check whether the video signal cable is too long. Generally, the distance of VGA signal cable should not exceed 40 meters (input end + output end), and the distance of DVI/HDMI signal source should not exceed 15 meters (input end + output end).
5. If the adapter is used, check whether it is functioning normally.
6. Confirm whether there is access to other devices except signal source, mixed matrix and display equipment, such as signal extender, converter, distributor, processor, etc. If there are other devices that can not be connected first, the signal source shall be connected to the matrix and directly output to display equipment. If the signal is normally displayed, other equipment failures shall be checked.