If you're having problems with your video cable, there are a few things you can try to troubleshoot the issue. First, check that the cable is securely plugged into the TV and the video device. If it's loose, tighten the connection. Next, check the cable itself for any damage or wear.
If you see any damaged wires or cracks in the insulation, it's time to replace the cable. Finally, try using a different cable. If you have a spare one lying around, swap it out and see if that fixes the problem. If not, the problem is likely with your TV or video device, not the cable.