Set up the multimeter to measure the resistance in your christmas tree lights by following the manufacturer s instructions.
How to test christmas lights with multimeter.
For this one requires a multimeter and of course the led to be tested.
But this doesn t always happen.
You will end up having two probes plugged in the multimeter.
If your christmas lights are fine the next step includes checking the power plug.
Place the probes of your digital multimeter at both ends of the power plug.
After learning about the basic details of an led the next step for any aspiring robot or electronic circuit builder is to learn about how to test an led which is much the same as the method used to test any diode with a multimeter.
On the male plug touch the remaining multimeter probe into one of the prongs.
When this happens use a non contact voltage detector to determine exactly which light bulb is faulty.
Testing it for continuity using a multimeter is a more reliable method and it won t burn out the bulb.
Continuity testing is also a reliable way to troubleshoot pesky string lights that have a habit of burning out the day before christmas.
A decent mid range multimeter will likely cost between 50 100 usd.
Check online or at your local hardware store for mid to high range multimeters which are more likely to have this feature than inexpensive models.
Warning if you lack a good knowledge of electricity it is best to limit your attempts to repair christmas lights to replacing light bulbs and fuses.
In some cases a faulty power plug is the main culprit for the absence of the current in the string of lights and identifying this problem early can save you a lot of time.
Sometimes a couple of bulbs or the entire light string doesn t light up when you plug the cord into a power outlet.
With this method you test continuity between successively smaller sections of the light strand in an attempt to determine where a bad bulb is located.
Christmas lights are wired to stay lit even if one of the bulbs burns out.