Christmas, Hanukah, and other festivals of lights benefit from lots of decorations. Unfortunately, when everything is unpacked each year, lights may not work. Fortunately, many can easily be fixed. Here's how.

How Does It Work?

Holiday lights are strings of low-wattage light bulbs that are designed to decorate an indoor holiday tree, the outside of a home, a fireplace mantle, a stairway, or anywhere else a homeowner wishes to add light and color.

What Can Go Wrong?

Holiday lights are relatively simple in operation, so the things that can go wrong typically are just as simple. Whole light strings may not glow and single bulbs may burn out.

Fix-It Tip

Bulb blown out? Don't throw away the bulb you think has caused a problem until you retest the string. The bulb may still be good.

How Can I Identify the Problem?

Fuses typically are located in or near the electrical cord plug.

First, let's take a look at holiday lights. If a string of lights does not come on at all, make sure power is on at the outlet. Plug the set of lights in another outlet to verify that the outlet is not the problem. If the string still doesn't light, test the electrical cord .

If the lights are blinking and you don't want them to, look for clear bulbs with a red tip or a different-looking base (these are blinker bulbs), and replace any you find with clear bulbs.

If the outlet and plug test good and the lights still do not work, check the string of lights from end to end until the whole string of lights works properly (see below).

Caution!

You can be shocked handling a broken bulb or the bulb's socket. Once you've located the problem visually, unplug the string of lights before attempting to fix it.

What Parts, Materials, and Tools Do I Need?

Replacement parts for holiday lights are available at most stores where holiday decorations are sold. And adhesives are widely available. To work on holiday decorations you may need these tools:

• Multimeter

What Are the Steps to Fixing It?

Locate the problem in a string of holiday lights:

1. Visually check each bulb in a string and replace any that are damaged or missing. Make sure that all screw-in bulbs are tight.
2. Plug the string into an electrical receptacle.
3. Gently tap each bulb to see if it flickers or causes the strand to flicker. If it flickers, unplug the strand and inspect the bulb and its base for obvious damage and replace if needed.
4. To locate and replace a bad bulb in a strand that won't light, use a bulb that you know works and, one at a time, substitute it for each of the bulbs on the string, replacing each bulb with the previous socket's bulb until the strand lights.
5. To locate the bad bulb in a strand that flickers, start at the end closest to the plug and touch each bulb until the flickering stops or starts. Replace the bulb and retest the string because the problem may be in the wires.
6. To locate a blown fuse on a light string, plug a working light set into the one that doesn't work. If the test set doesn't light up, replace the fuse in the nonworking strand or replace the strand.