With your what? Many people do not realize that some string lights come with fuses. Fuses are important safety features that can prevent overheating, electrical damage and even fires should there be a malfunction in your string lights or electrical system.
If you need to change your fuse, make sure you first identify the reason it gave out. Then, when you determine the cause is not a safety hazard, you can change the fuse and enjoy your beautiful string lights again. Here is a quick and easy guide from the Paper Lantern Store on How to Change a Fuse in a String of Lights.
First, you need to locate your fuse. Usually it will be in your lighting stringer's plug. Typically, you just slide the door open on the plug, pushing it open in the direction that the arrow on the outside points.
Once you have opened the plug, there may be a spare fuse inside in addition to the damaged one you need to replace. If there's a spare, great. If not, you can determine what size replacement fuse you need by looking on the outside of the plug, where the proper fuse should be noted. If you don't have one handy, you can buy a replacement at a hardware store or lighting store.
Remove the old fuse by prying it out gently with a small screwdriver. Then simply install the new fuse, making sure you hear a snap that ensures you have properly installed it. Slide the cover shut.
Now, all you have to do is test your light string. If there is an obvious problem, unplug it and find the cause.
Most of the time, there will not be a problem. With a new fuse, your string lights should be working properly, and you, your family and friends can enjoy the beauty of your string lights once again.