Decorating your home and Christmas tree with strings of lights is a common way to celebrate the season. Sadly, Christmas tree lights don't last forever, and it can be difficult to determine whether your entire string of lights should be replaced, or whether there is something you can do to salvage them. When Christmas lights burn brighter than usual and then go out, take steps to investigate and fix the problem.
Inspect the lights that burned out. If they are blackened on the inside, the lights are unfixable and need to be replaced. If not, continue troubleshooting.
Check plugs to make sure light strands are tightly plugged into each other and the power outlet.
Move your hand over the strand of burned out lights. If any of the lights flicker, replace them with a new bulb.
Inspect the chain of lights to see if there are any missing or broken bulbs, which could cause the entire string of lights to go out. Replace any missing or broken bulbs that you see.
Tips: To prevent future problems with your Christmas lights, make sure to replace burned-out bulbs as soon as possible. Extra wattage from these bulbs can overload the rest of the bulbs on your string, causing them to burn very bright and then burn out, ruining the entire string.