Find a bad LED in Christmas light string

Figuring out that part of your string of LED lights doesn't work is no fun. Figuring that out after you've hung them on the roof is even less fun. Test your lights out before risking life and limb to be the brightest house on the block, and if you happen to have a dead section in your string of LED lights, use this method to find the faulty LED.

Happy decorating!!!

➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖

If this helped you out and you'd like to show your appreciation, donations are accepted :

[roxannreid-rojas]

Love this - everything else I looked at required that I buy a more expensive item to fix the leds. This was so much easier!

[JM-yxlm]

This is the better tutorial for led lights. Others did not tell me the way the voltage went through. Good deal man. Now we need a video on icicle lights.

[justbs]

Great tip! Using your guide I was able to fix my string in less than five minutes! 🙂

[bobkilley]

Great advice to use the volt meter and explain how to do it. I had the misfortune of 2 bulbs with poor connections and it was impossible to solve the problem until I used the volt meter. Many thanks!

[reedrosenberg]

actual successful application of a divide and conquer algorithm. somebody get this man an honorary CS degree (if he doesn’t already have one) for the greatest DIY YouTube video of all time

[shelbymachine]

I already had a volt meter, and your video helped me find the bulb with the loose lead wires. They still blink off because it's a bad design, but I know which bulb it is and it doesn't blink off unless there's a lot of wind. Thank you for taking the time to share your knowledge.

[CAMPFIRESKY]

THANK YOU - I have one string with the middle out, and another string with the middle the string "blinking" off for about 10-15 seconds and then back on. Driving me nuts ! I'm off to get a volt meter. THANKS AGAIN !

[Chris-qlsq]

Thank you SO much for making a video that was both easy to understand and simple to duplicate the test!

[rolfingo]

Helpful and informative. Now I have the motivation to work on my broken sets. THANKS!

[peterfrangos]

Hey Dustin, I had a slightly different issue with my set of LED lights. Plugged them in this year, they lit up but they were no where near as bright as they should have been. I decided to give your voltage drop testing technique a whirl and it worked. Was getting maybe 30v AC from the end almost all the way to the beginning of the string. Then bang, 120v on one back to 30v on the next bulb. Swapped out the one in between with a replacement and the string lit up like last year! Guess that diode half fried and was acting like a big resistor. Anyway thanks again.

[vamosaveralninoDios]

Of all the videos to help fix my expensive LEDs yours was the very best. Thank you

[daver.]

Thanks for the info. I didn't know you could find a bad led by checking only the socket. This video will save me lots of time.

[npolite]

Great video. Not only saved my light strings but also $25 for that Light keeper tool. I have a few free multimeters from HF so this worked out great.

[edr]

You are THE MAN!! Saved me a few bucks and a lot more frustration. I put my trusty Radio Shack (RIP) multimeter to work once again. THANX !

[opiewanslightsaber]

Thank you! Way faster and easier than doing one bulb at a time!

[mooglemy]

Super simple and thorough explanation. I can fix my friends prop from memory. Good job and than you very much.

[pgcorky]

Kudos, Dustin. It all seems obvious once I see it done. Much appreciated!

[pamelahughes]

Thank you! Exactly what I needed. Your display showing half the lights off was my exact problem!

[sasteak]

Great trouble shooting tips. I was able to locate the bulb that was causing half my light strand not to work while the strand was still on the tree. Measuring voltage in various sockets to find the bad bulb worked well for me. Thanks for the help.

[lisamcdannell]

Great job plainly explaining this !!!!