how to check christmas light bulbs

If you have an LED string of Christmas lights and one of the bulbs is not working, you can test the bulb to see if it's defective or just not receiving power. First, make sure the string is plugged in and that there are no other bulbs that have blown. If there are no other bulbs blown, then remove the bulb that is not working and test it with a multimeter or bulb tester. If the bulb is defective, it will not light up on the tester. If the bulb is not defective, then it's possible that it's not receiving power.