LED light strands have many advantages over traditional Christmas lights. Tthey use less energy, last longer, burn brighter and don't get hot. Even so, LED lights, like any other Christmas lights, can burn out or show other common problems. If you are familiar with troubleshooting traditional incandescent light strands, you can use many of the same strategies to fix your LED lights.
Check your power outlets and extension cords to make sure that your lights are tightly plugged into the outlets and other light strands. Try plugging in another appliance to make sure that the problem is with the lights and not the outlet.
Check the fuses in the female end of your light strand to see if any filaments are broken. If they are, replace the fuses.
Check that the prongs in your electrical plug are making full contact with the circuit. Gently spreading the prongs outward should fix this problem.