Troubleshooting Christmas Lights: String Faults

Homeowners all over the world celebrate Christmas by decorating their homes in strings of Christmas lights. Every year the industry releases new types of lights and styles of bulb. Christmas lights in long strings are a long-time choice that still prevails.

Christmas lights are more complicated than they appear. Christmas lights are not meant to last for more than one season but the consumer likes to buy a series of strings and continuously use them. With this amount of activity; strings are prone to failure. This article will help you troubleshoot string faults in your Christmas lights.

How Christmas Lights Work

You have to think of Christmas lights as what they are: tiny light bulbs. A typical light bulb works by allowing electricity to heat a metal filament inside the bulb. The metal filament is heated up to the point that it glows. The hotter the filament gets determines how bright your light will be as well as how long a bulb may last. Christmas lights work on the same idea but on a smaller scale. A string of Christmas lights can go out when one bulb fails. Each bulb on a string of Christmas lights has a shunt at the bottom which is supposed to conduct the current when a bulb fails. Unfortunately, the shunts rarely actually work.

Start with the Bulbs

The bulbs on the Christmas lights are generally the problem that causes full strings to fail. The shunts on the bulbs are meant to eliminate this issue but since the shunts frequently fail, whole strings will go out making it difficult to diagnose which bulb is actually faulty. Plug the string of Christmas lights into the wall socket. If the entire string is out, start with a bulb at the end of the string. Look for the lights that have a splash of red on the bulb near the bottom. These lights are key. If half the string is out, look for the dead bulb closet to the end. If you replace the end bulbs and the string of lights still does not work another bulb is the problem. A bulb tester made for Christmas lights will be a worthwhile purchase.

The Fuse of the Christmas Lights

Christmas lights have a small fuse box close to the plug end and are usually one in the same thing. If a string of lights fails to work, the fuse may be bad. You can use a screwdriver with a flat head to pry the small door open. The fuse is made of glass so before removing it look for signs of charring. If the case is damaged then replace the lights. Remove the fuse in a straight line with gentle pressure, then replace the fuse with a new one.