First, try plugging it into another electrical outlet. If that's not the problem, it could be a loose or broken bulb. Most string lights have two tiny fuses inside the plug. Typically, a box of lights is also packaged with a replacement fuse or two. via
How do you fix Christmas lights when half string is out? (video)
How do you know which bulb is out on Christmas lights?
You can tell which bulb is out on your string of traditional Christmas lights by looking for the bulb that is “burned out” by looking at the tiny little filaments in the light bulbs to see which bulb is “burned out” or has lost it's filament. Many times the bulb will be “smoked” as well. via
How do you find the bad bulb on Christmas lights without a tester?
Pull out one bulb at a time, and stick a piece of folded up foil into the bulb socket. If the lights come on, you know that's the bad bulb. If they don't, put the bulb back in and move on to the next one. via
Why do Christmas lights all go out when one bulb blows?
In this setup, when a filament within any one bulb blows out, it creates an open circuit in the wiring. As we mentioned earlier, when a circuit is incomplete, or open, electricity fails to pass through any of the wire, causing all the lights to go out. via
Why are half my LED Christmas lights out?
If one of your LED light strands isn't working, it's probably just because it has a bad bulb. If one bulb dies, it can cause the rest of the strand to stop working. The only way to fix the problem is to find the bad bulb. That means pulling off each bulb, replacing it with a good bulb, and plugging it in. via
Why are half Christmas lights out?
A light bulb has come out of its socket or is half out of its socket and it has brought down the circuit. If a bulb is missing in a circuit only the bulbs in series of it will go out. That's how you can lose 1/2 or 1/3 or 1/4 of the string. via
Why is a section of my icicle lights out?
If large sections of lights are not getting power, part of the strand's circuit has gone bad. This means you will need to replace the entire strand. via
How can you tell if a Christmas light fuse is blown?
What causes a whole string of lights to burn out?
If one bulb in a series is defective, loose or missing, the circuit is broken and the series won't light. Otherwise the other bulbs have to handle the extra voltage, which can cause them to burn out faster. Lights can also go out if a fuse burns out, but that will darken the whole string. via
How do you know which LED bulb is bad on Christmas lights?
Finding Bad Bulbs on LED Christmas Lights
Starting at one end of your strand, or in the dark portion of your strand, use your voltage detector or light tester to locate the faulty bulb or dead length of wire. via
Will Christmas lights work if one fuse is blown?
Blown fuses are one of the biggest culprits of broken Christmas lights — especially if the entire chain of lights is non-functional. The good news is that they can easily be replaced! If the fuse is good, you should see an unbroken strand of wire running between the two metal contacts. via
Where is the fuse bulb on Christmas tree lights?
The underside of the plug is where the fuses are located. Look for the arrows pointing on the socket. They should be pointing away from the cord and towards the male end of the plug. Locate the sliding door that conceals the fuses. via
Why are there two fuses in Christmas lights?
Typically, these strings of lights have two tiny fuses, one in each side of the AC line, located inside the AC plug. The fuses are intended to melt or "blow" before the copper wires in the string could melt or cause a fire from overload. via