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Here's how to fix your broken Christmas lights

You for the win over busted bulbs

There is one red bulb popped out of a multicolored string of Christmas lights Credit: Getty Images / JJ Gouin

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No matter what holiday you celebrate, there's a chance you may find yourself tangling with Christmas string lights this season. Burned-out bulbs, strands that light up only halfway (or not at all), and let's not forget those knots.

You don't have to go too far down the internet rabbit hole on Christmas lights before encountering complicated electrical diagrams and DIYers offering tips on how to rewire your plugs. Fascinating? Yes. Is it how I want to spend my December? No.

For those of us not quite as skilled in the electrical trade, here are some common problems with string lights, both incandescent and LED, and how to solve them.

What to do when bulbs are out

One bulb is out, but the rest of the string works

You’re in luck. This is the simplest fix, requiring you to simply swap out the bulb for a new one. Assuming your bulbs are removable—not hardwired, as some LED strings are—there should be spare bulbs in the original box. You may also consider buying a strand of matching lights solely as a source to pilfer extra bulbs.

Experts have an additional piece of advice here: If you have one or two burned-out bulbs on an otherwise functioning strand, don't ignore them. The remaining bulbs could be contending with excess voltage that shortens their lifespan.

If only half the strand is out

If half a strand is working and the other half is not, you probably have a loose or broken bulb.

Start with the first unlit bulb and work your way down, wiggling them to check for looseness. If it flickers, that's your cue to replace it. If not, you have the more tedious job of going down the row of unlit bulbs, one at a time, and swapping them for a known, good bulb until you find the culprit. You'll know it when the strand lights back up.

If the whole strand is out

If you find yourself with a dead string of lights, a number of things could be wrong. First, try plugging it into another electrical outlet. If that's not the problem, it could be a loose or broken bulb. See the previous section for instructions.

The problem may also be a bad fuse. Most string lights have two tiny fuses inside the plug. Typically, a box of lights is also packaged with a replacement fuse or two.

To replace a fuse, take a small set of pliers or flathead screwdriver and slide open the cover. Then gently pop out the fuse and replace it with new ones. Slide the cover closed and plug it in.

If you have only one extra fuse, try replacing them one at a time. If you need more than one, replacements are typically available at most hardware and craft stores during the holidays.

Illuminated white string lights are sitting in a person's two cupped hands
Credit: Getty / kenlh

Tangled Christmas string lights really is its own special brand of torture.

Specialty repair tools that may speed things up

Unless you're replacing a single burned-out bulb you can easily identify, hunting down the problem bulb that killed your whole strand is dull work.

A light tester, like the one from Light Keeper Pro, is relatively simple to operate and will save you a lot of time. Spare fuses and bulbs are also recommended—just make sure they correctly match the strand.

Dealing with non-removable bulbs

Some LED string lights have non-removable bulbs. Contrary to what you may think, this can be more of a boon than an inconvenience. In fact, it's a standard for commercial lighting due to their higher reliability and longer lifespan.

Even so, non-removable bulbs can eventually burn out or become damaged and take out the whole strand. For those cases, Ulta Lit LED Keeper light set repair tool seems to be the tool of choice.

Impossible tangles

Tangled Christmas string lights really is its own special brand of torture. Unless you've been practicing your escape routines, you could be at those knots for a long time. To make matters worse, vigorous tugging on the string will only further damage the bulbs.

Sorry to tell you now, but prevention really is the best medicine. Save yourself a headache next year by wrapping them around something like a piece of cardboard. Just cut a small slit to stick the electrical plug through, wrap your lights around, and then poke the other end through the same slit.

Boom, you've just repurposed some cardboard and given yourself an early gift for the next holiday season.

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