how to tell what christmas light is out

To determine which Christmas light is out, you can use a simple method called "swap-and-test." First, identify the specific string of lights you want to check. Then, turn off the power supply to the lights and carefully disconnect the string from the electrical outlet. Next, take each bulb out of its socket one by one, and test each bulb individually by connecting it to a different socket. If the bulb still does not light up, then that bulb is the one that's broken or burned out.