Don’t you hate it when you finally get all the lights strung  and plug them in – ready for the big Ta-Da! – but all you get is a big WAH-wahhhhhh?
Or what about when you realize the lights you put up that once worked, suddenly don’t?
First, check each bulb to see if it is loose in the socket. Do this by gently pressing each bulb into its socket. Even though lights are often designed to work if a single bulb goes out, they won’t work if a bulb is unplugged.
Once you’ve tightened the bulbs, plug the string back in. If the string still doesn’t work, unplug it and check the fuse. Most strings have a fuse built into the plug. Remove the fuse and check that it isn’t burned out. If it is, replace it. Most light strings are sold with extra fuses taped to the string somewhere in a very small plastic bag.
If you have success with the above techniques but find you’re short on parts, relegate one of the light strings to salvage status and use those bulbs and fuses to get the rest of your light strings in working order.
Hey, we wouldn’t string you along -- know how to troubleshoot your holiday lights and you’ll keep a twinkle in everyone’s eye this season.