Don’t let a broken strand of lights zap your holiday spirit
When troubleshooting Christmas lights, start by looking for external issues, such as a bad outlet or tripped circuit breaker.
If you find damaged wiring, it’s best to replace the entire light strand.
Use a Christmas tree light tester or non-contact voltage tester to find bad bulbs.
If you don’t have a tester, swap out individual bulbs and test the strand until it works.
A faulty light strand can be a major holiday headache, especially if you’ve already spent time hanging it or incorporating it into your festive decor. Luckily, you can learn how to find a bad bulb in Christmas lights before you resort to the tried-and-true (and time-consuming) method of replacing and testing each individual bulb. This guide will walk you through how to find the bad bulb in Christmas lights before calling a professional holiday decorator to solve this issue.
If your lights are plugged into an extension cord, start by checking whether the cord is the source of the issue. Unplug the cord and plug the lights directly into the outlet to see if they work.
In some cases, the issue is the circuit breaker or the outlet rather than the strand of lights itself.
First, if your outlet or extension cord has one, check your circuit breaker to ensure it's set to "ON."
Next, plug in a working device into the outlet to verify that it's functioning properly.
You can also use a continuity tester to test the outlet.
If you believe the outlet could be faulty, it's best to contact a local electrician to come and fix it.
To check a strand of Christmas lights for damaged wires, start by unraveling the lights and inspecting them for broken wires and sockets. If you find any wires poking out, it's best to replace the entire strand.
If all the lights on your strand aren't working, it's possible that a blown fuse is the culprit. Testing and addressing this problem is relatively simple.
Find the male end of your lights.
Then, use a screwdriver to slide open the housing cover and access the fuse.
Check the fuse for signs of burning or a broken filament.
If you notice any damage, replace the fuse.
Once the new fuse is in place, slide the cover closed and plug the lights in to see if they work properly.
Another common reason for malfunctioning Christmas lights is loose bulbs. Here’s how to troubleshoot:
Unplug the light strand.
Inspect each bulb by gently pushing them into their sockets to ensure they are properly seated.
If you find any bulbs that are not fully seated, replace them with new ones.
Test the lights again.
If you've exhausted the previous solutions and your lights still aren't working, try testing your Christmas lights with a Christmas tree light tester to find the bad bulb. Note that there are different models for LED versus incandescent lights, so be sure to purchase the correct tool based on the type of lights.
Start at one end of the strand or where the lights are not working.
Follow the instructions on the tester to test every bulb, even the ones that appear to be working.
Discard any bulbs that don't work and replace them.
A non-contact voltage tester works similarly to a Christmas light tester, as it checks for AC voltage in your Christmas lights. This method of testing Christmas lights makes it easier to identify a faulty bulb without the hassle of removing and replacing individual ones.
Plug the lights in.
Choose a section halfway between the end of the malfunctioning section and the section that still works, and hold the probe of the tester near the wires in the male plug.
If the tester beeps or flashes, it means that section works.
Repeat until the device doesn't beep.
The bulb next to the one that doesn't prompt a response might be the faulty one, so you can replace that bulb to see if the strand works.
If all else fails and you don't have a Christmas light tester, you may have to test each bulb manually.
Unplug the light strand.
Removing one bulb at a time and replacing it with a new bulb.
After each replacement, plug in the lights to test them.
Continue this process until the problem resolves.
If the lights still don’t work, your best bet is to get new ones.
