HOW TO EASILY FIND BAD CHRISTMAS LIGHT BULBS using a non contact voltage tester

Updated video that addresses some people's feedback such as not needing to check every bulb, as well as using another tool/method if preferred: • HOW TO TEST AND FIX CH...
The method used in this video requires a Non-contact voltage tester (affiliate link):
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Time index
0:22 How the lights are wired and why some can be off with others lit
0:59 How a non contact voltage tester can help find blown bulbs
1:58 Demo using the voltage tester to find the bad bulb
5:30 Use a binary search to find the bulb faster without testing every one
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Videos are mirrored at LBRY/Odysee: odysee.com/@GadgetReboot:4

[@TheAMVDJ]

The immense feeling you get after plugging in a lightbulb and the whole strand finally lights up is indescribable

[@spammerscammer]

They made a movie about it.

[@HestiaBHN1]

Can't wait to experience this! Would orgasmic describe it?

[@truthbot8907]

@@HestiaBHN1 It’s beyond that!

[@nightlightabcd]

Or the disappointment when one does exactly as shown and nothing!

[@THOMMGB]

When all the lights come on and stay lit, it's called the Clark Griswold effect.

[@brakubee]

Dude it's people like you who take time to share some good knowledge that many of us love you tube. Thank you for this. Made perfect sense. Worked like a charm.

[@GadgetReboot]

Glad you got something good from it!

[@snowgeezers5771]

@@GadgetReboot does this work with led bulbs as well?

[@GadgetReboot]

@@snowgeezers5771 I haven’t had to do it myself but it should work just the same to locate the fault when the circuit is broken by a bad LED. Here’s an instructable somebody did using this approach with LED lights. www.instructables.com/id/LED-Christmas-Light-Repair/

[@thehammer4625]

@@GadgetReboot I just picked up a Light Keeper for LED bulbs and had to replace about 50 bulbs, it took me about 3 hours, but it did a great job. I probably have 25 light sets of 50 lights and after 3 years almost every one had half the lights out. I also have some incandescent string lights and will get one of these testers. Thanks for the video.

[@marshallgeller8025]

I actually retrieved my lights out of the trash bin and got them to work following these steps. Thanks so much.

[@squirrelydan3]

I still can't find the burnt out ones even after this method. There's a special place in hell for the designer of Christmas lights.

[@equisequis.55]

they designed them that way so you can buy more forever.

[@kcgunz1523]

if no bulb is blown,2 fuses are in the connector that are prob blown. its a non polarized plug

[@julievillar6649]

@@kcgunz1523 Is there a youtube or link to show how to test and replace the non polarized plug?

[@julievillar6649]

btw- the string i have is on a santa from 1989 [20 lights] and the fuse is a strange little plastic square with 2 little wires.... My thought is to replace the plug with an old light set plug that has newer types of fuses because i don't know where to find or buy the other type of fuse.... i can send a photo... E99566 fuse plug

[@ZenithAstrology]

Dan Hill Why do they break so easily? Lol

[@jjw3kds]

If only Clark Griswald would have known of this sorcery. Great idea. Thanks

[@WatertownFilms]

Every year I pull this same video up to figure out how to fix my lights again. Thank tou

[@johncoops6897]

When troubleshooting series strings (or anything wired in a similar way), always start in the CENTRE. That tells you which half of the string is dead. Then test at half way within the dead half section... in that way you can isolate which (quarter) section contains the fault. Then drill down further in the same way. So in this case of 50 lamps you'd first test to determine which is the active (line) end of the string, then test bulb number 25. If that bulb has power, then test Bulb 37, if that works, test Bulb 43, etc. EDIT: That's the method used in the follow up video (linked in description).

[@GadgetReboot]

yeah I mentioned near the end that’s what I would do normally but I should have done it that way all throughout. In the follow up video I did a year later, I did it the right way finally.

[@jamesbelshan8839]

@@GadgetReboot No, I think your series approach was the right way for a newbie to learn the logic behind the method, before you move on to the advanced bisection method.

[@chickbornheim9766]

You said it much more concisely than I did. It's called a "binary search."

[@cchavezjr7]

Doesn't matter, it will still be the last bulb you check that's dead

[@nunureds837]

@@cchavezjr7 well of course, cuz once you find the dead bulb, why would you keep checking 😆

[@toonchi3357]

When I started this video I had 1 burned bulb, after the video finished I have 20 smashed bulbs because I stomped it out .

[@thomasdragosr.841]

Now, go buy a new string...

[@brinkcraven837]

Hahaha that sounds like my life

[@nickcoady7997]

Love it! That sounds like me! :-)

[@baggieshorts1406]

I really tried... but you know the saying... if at first you don't succeed......... give up and go buy some new lights...

[@baggieshorts1406]

They are wired in series, so if one blows none work. If they were wired parallel then those that work will light, faulty ones will not light.

[@scottfurlong5475]

I'm an electrician who makes a living at diagnosing electrical issues in old and newer homes. It's very rewarding work and I enjoy it a lot. I'm proud in saying that in 11 years we've yet to walk away from something we couldn't find and fix. I have 7 or 8 pieces of electrical diagnostic equipment and experience. I still absolutely despise those chain type Christmas lights.

[@ChrisKay54]

Amen to that, brother.

[@ChrisKay54]

I get 2 to 3 years out of them and throw em out once half the string doesn't work. Sometimes it's the cheap line they're on and not bad bulbs.

[@chrisfuller1268]

I'm a hands-on Electrical Engineer and have debugged incredibly complicated systems, but Christmas lights have always been too much of a pain! Lol

[@hmax1591]

I thought that christmas lights or any other lights arranged in a string no longer did that? Aren't string lights connected in parallel so one burned bulb doesn't shut the rest of the string as it was for in series?

[@scottfurlong5475]

@@hmax1591 I guess there could be that type out there but the sets I have are two, three or four series loops put in parallel with each other. Lose one bulb and basically a short section of the string goes dead but not the entire string. Find a bulb socket on your set that has more than two conductors going into bottom of it, this indicates a set with parallel loops of series connected bulbs. I'm much prefer the old sets of Christmas lights where the sockets pierced the extension cord type cable. If a bulb goes the rest stay on.

[@garrettmccleary]

This dude deserves a medal! Bravo my man thank you for saving me so much time and frustration

[@dwp1970]

Thank you! I did consider myself somewhat knowledgeable at one point in my life but as I get older I realize how little I know about everything. Merry Christmas!

[@robertlalum1461]

I was an engineering technician for an r&d company this is ingenious I would have never thought about this

[@meangreen7389]

Sometimes it takes a lot of words to explain something simple but you’re articulate and pulled it off, thanks for sharing this technique.

[@0623kaboom]

easier technique ... as you pull the string out of the storage box and get ready to untangle it ... look at each bulb if the tip is black change it .. 10 minutes and 10000 lights later your done and all it cost you was the replacement bulb ... those type of bulbs use afilament that carbonizes when it blows ... leaving soot in the bulb at the top ... a true LED when it burns needs to be tested those or just low voltage lights technically ..

[@meangreen7389]

@@0623kaboom - You also have a good technique. Thank you for sharing your tip.

[@buddyboy4x44]

I have viewed many "how to finds" like yours and yours is, in my humble opinion, the clearest and best. Thank you.

[@GadgetReboot]

Thanks for the feedback! I try to do the best I can and share whatever insight I have, hoping somebody gets value out of it.

[@timsawyer7443]

What a lifesaver! I'm in charge of the "official" Christmas tree for our county, and every year we end up buying new strings because of a bad bulb (or two, or...), since nobody has the time or inclination to go through bulb-by-bulb and find the problem child. This will save our Chamber if Commerce (all volunteer, self-funded) a good bit of money over the long haul. Thanks!

[@GadgetReboot]

Glad to be of help, hopefully lots of time and money are saved.

[@Cloudman572]

A somewhat quicker way is once you know which way is coming from the live (ie test the 1st and last bulb and the working one is the live side) then go to about half way in the string of bulbs- if the bulb is still seeing live go to the 3/4 way in the string. If not seeing live on that 1/2 way bulb go to about 1/4 of string and test. Keep halving the string to find a bad one (or multiples).

[@barrybegley5379]

Even as a retired electronic technician, I don't think that I would have thought of this approach. It's quite ingenious actually. Just shows that we can always learn something New. Thank You for the clever incite. Barry Howard Begley

[@JFM1170]

As an Electronic Tech I have one of these probes and they give false readings....nothing better than the VOM. Never found a light set I couldn't get working, a simple series circuit with the VOM.

[@barrybegley5379]

@@JFM1170 There usually are more than 1 way of accomplishing most tasks, and the multimeter can certainly be up to the task as well, but by working both ends of the string with this wireless voltage sensor and then going to the middle, the process can immediately be cut in half. When the defective half is discovered, then the middle of that portion could be tested, thus honing in on the defective culprit. While these voltage sensors can be quite sensitive, but by corralling the cable mass, and approaching near the bulb itself with the instrument, it could be a huge timesaver from pulling dozens of bulbs on a large string. I still think it is a GREAT idea !

[@JFM1170]

@@barrybegley5379 Barry you are right it can be easier I have one of the testers and I always go back to the DMM or the VOM I have found the tester is very unreliable. When I test a string I put 1 lead in the neutral slot and work around the string about every 5 bulbs you will always have 120v until you find the open, that's just my method. I guess I am still old school I still like the analog Simpson meters.

[@barrybegley5379]

@@JFM1170 Well...Whatever works for You. I am curious, though. Where are you picking off the individual voltage drops around the loop of bulbs if the string happens to have molded sockets. Are you pulling the bulb from the socket under test to get at the contact or is the cord being compromised to pick off the presence or absence of a voltage?

[@JFM1170]

@@barrybegley5379 I put 1 probe in the neutral slot then foam the hot side I walk up the string about every 4 or 5 bulbs, You should get 120v until you pass the open. I will then back track pulling each bulb until I find the 120v. When you find the 120v you have the bad bulb or the open part of the circuit, The voltage drop will always be 120v until the circuit is complete, I usually do a 4 or 5 bulb skip doesn't take long to go back. You still have to go around the string in case more than 1 bulb is the problem. Nice Chatting Good Stuff.

[@DigiTiLMon]

Thanks bud! Was able to use the tester on my electric pliers to follow along on my pre-lit Christmas tree to find the gremlin!

[@rominhawk3949]

Actually, this is a very good presentation of how to find a bad bulb. I followed your instructions and flipped the plug to switch the hot wire; and was able to find the bad bulb. But, it was a bit of a learning curve for me; but, once I got it, I figured what to look for; because the tester was sometimes not chirping for a particular bulb, and I'd go back to the previous one and it chirps; I come back to the bulb that wasn't chirping only to find that now it's chirping. And for one of the sockets, I had to use the shunt fixer to fix a bad shunt. I had to change 10 bulbs. Thank you very much for a great presentation.

[@fishontv6834]

Bro. I was playing around with a ohm meter for like 2 hours trying to find the break. No idea why my brain didn't think 'Use the non-contact voltage tester'. I'm so used to working in DC with LEDs, my brain didn't click. Thank you. After watching this video for like 2 minutes, I went downstairs into the shop and found the break in like a few minutes. It wasn't a light, but a contact inside the housing that was pushed down and wasn't making contact. The lights have shunts in them so I knew it probably wasn't a broken shunt AND light. I love KZbin :) My kingdom for parallel LED light strands. Serial LED light strands are as evil as printers.

[@darrinrentruc6614]

The best vid on the quickest way to get these fixed.

[@arsena7538]

Great video. The part where you flip the plug was what I was missing. After doing that, I quickly found the burnt bulb. Thank you!

[@alicearmstrong5082]

Just knowing that a voltage tester can help find the burnt out bulb without pulling out the bulb was a time saver. I strung my lights before testing them and didn't have to pull them down to find the one pesky burnt bulb. Thanks for the tip!

[@0623kaboom]

does NO ONE actually spend the 2 minutes to look at the tip of each bulb for black soot ... the tell tale sign of a burnt bulb ... yup those christmas leds are filament bulbs and when they blow they burn the filament and leave a sooty residue inside the bulb very easy to see ...

[@alicearmstrong5082]

@@0623kaboom Not for me..my eyes are not that good. It was an easy task after my lights were strung to use the voltage tester to fine the burnt bulb..

[@macksterp4112]

Ran to the store and bought my very first non contact voltage detector for LEd lights because of your video. I can't wait to see if I am successful at saving some strands and money! Thank you for the clear explanation and demonstrations.

[@benwarner5389]

DUH! Why have I struggled with finding problems in bad lights for all these years! Yes, I have the Light Keeper and it works but seriously why didn’t go to the electrical drawer and get my non contact tester!! I think have 3 or 4 of the things in various tool boxes and tool bags! Thank you!

[@eugenepolan1750]

A good place to apply the Fibonacci search technique! Check both ends, then check a place offset from the middle - you have the potential of zeroing-in on the bad bulb in fewer moves.

[@Arthurgarzajr]

I think this is binary search

[@PortalFPV]

I've known of this trick for a many years now, but never could get it to work. Having hot on the correct side & shielding where the little nuggets of wisdom I was missing

[@grandinfinite5921]

The simplest explained of all videos I've ever seen! Thanks.

[@desertodavid]

KZbin just recommended this today December 26th 2021-- the day after Christmas. Christmas lights have been up for about a month now. Good job Susan.😏

[@GadgetReboot]

The algorithm needs a lot more work

[@rong1924]

Thanks, I have an old set of lights that has a twinkle mode I really like and is just the right length for my outdoor stairs. It's getting finicky to maintain so this video is a lifesaver. This is the first video that has clearly explained how the voltage tester works.

[@brikshoe6259]

I like the use of the non-contact voltage detector. But there is a faster way to troubleshoot a large string: once you have figured out which is hot and which is neutral, start in the middle, at light 25, if that is good, go to light 13, if that is good, go to 6, etc. Keep splitting the balance of lights in half and you'll find the bad one in a handful of checks instead of checking all 50 bulbs.

[@CHT420]

@@clopez4280 yes I find this a lot nowadays 🧐

[@matthewdavis9437]

He actually explains this right at the end of the video. Great way to show that you didn't watch it all. Lol

[@brikshoe6259]

@@matthewdavis9437 That is quite clearly not how he explained it but you are welcome to interpret it however it works for you.

[@IrrationalBstrd]

It's faster and easier to just look at them... When the bulb burns out it usually leaves a black mark. LoL

[@_suki_]

👌👌

[@davidyoung1610]

Worked like a charm👍🏻!! Saved me from having to buy another prelit tree this Xmas. Thank you!

[@SlaveToMyStomach]

Video is 3 years old but I'm just seeing it now and at just the right time of the year. Thanks for sharing. I have one of those AC detectors and never thought of using it on Christmas tree lights. I also never thought about shielding the wires.

[@silver-phoenix]

Thank you very much! Happy Holidays & may your lights shine brightly!💡

[@chickbornheim9766]

great video. May I suggest a slight shortcut (requires less tests?) Use a binary search to identify which half of the string the break is in. You do it by testing the middle lamp of the string for power. Call the half string between plug and middle lamp string A and call the second half (from the middle lamp to the end) String B. After testing the plug test the lamp at the middle of the string. If there's power, the problem is in string B. Test the middle lamp of string B (i.e. 3/4 of the length of the string.) If there's power, divide the remaining lamps in two and test again. Once you find a middle lamp with no power, you know the problem is in the first half of the string you are currently testing. If there's power, it's somewhere between the lamp you are testing and the end. Keep testing the middle lamp of each substring until you find the problem. You'll test far less lamps to find the problem. Saves a lot of time.

[@TagiukGold]

Yes. I came to suggest the binary search.

[@thepotbellyninja]

He mentioned this near the end of the video.

[@lobuxracer]

This is commonly called the half split method and is taught in all electronics training to save LOTS of time. I learned it in Air Force fundamental electronics in 1979 and it wasn't new then.

[@RebelChannel42]

I use a flashlight and look for the broken filament. Saves even more time.

[@BradBo1140]

I’ve been trying to fix these for years. I even bought the kit to check bulbs. Now I understand flipping the plug and how the circuit can fool you if you flip the bulb and how to shield. Now I won’t be running these to the recycle by the dozen! Thanks so much. By the way, my wife is crazy for lights. We even have 6’ icicle lights coming down around the house from the gutter. I’ve had to pull 2/14 from a source with plug receptacles every three strings to handle the series load and mount them under my overhang.You cant miss our house!!!!

[@0623kaboom]

me i just get them from the neighbours as they toss them out ... look at each bulb and replace the black tipped ones and poof free string of lights ... ok I buy 20bucks of replacement bulbs a year BUT havent bought a string of lights in over 20 years ... simple easy cost effective check .. no gear no fooling around ... just look and pull the burnt bulbs and replace ... then untangle and plug em in and string em up

[@lurklingX]

AMAZING, thank you! I watched some other videos but this was so concise and to the point, and that diagram was fantastic. Saved for future reference!

[@ndcoach29]

I really needed this a few weeks ago when i went light by light, LOL!! I’ll get busy prepping for next year, thanks!

[@Hobby-zn7ce]

Exceptional communication and functional expertise. Nice job!

[@MegaTapdog]

i used to do it this way, ended up buying a lightkeeper tool and it was the best ever. i liked it so much i bought more for my family, it has a built in detector, a shunt activator, bulb tester, fuse tester etc. all built in. it’s like a crazy swiss army knife for christmas lights.

[@GadgetReboot]

I got one a year after making this video and then I made another video showing how to use it. It’s especially good when the lights are already tangled up on something like a built-in Christmas tree light or a garland.

[@aladincarpetcleaning6416]

Thank you! I never thought of the voltage detector method. It really helps frugal guys, like me, keep the reputation!

[@therealbadbob2201]

You made this absolutely simple. Thank you.

[@Polarcupcheck]

Stellar explanation. Fixed my shimmering lights strand using this exact method and a 9 volt battery to make sure the new bulb was good.

[@Marcoosianism]

A 9 volt battery can more often than not burn out a good miniature christmas tree bulb. Try using at most two 1.5v in series.

[@metalhalide4043]

Ingenious method that works, saved me hours..

[@joelcolon5060]

Thanks for sharing. Was getting ready to go to Home depot for new ones but decided to give this a try and was able to find the burnt light in 2 minutes. Saved me a trip and $$

[@terrykizer6755]

Thank you! You helped me fix Rudolph. Momma is happy! Happy 2019

[@GadgetReboot]

Glad it worked! Happy new year

[@squiggyg.8415]

I started celebrating Hanukkah just cause there’s less lights to figure out

[@carycoller3140]

😂😂😂😂

[@The_Sweep_Life]

Lol

[@STho205]

🕎

[@SonTran-lb8md]

Thanks for the awesome video. I just wanted to share what I learned about buying replacement bulbs based on the number of bulbs you have on your string of lights: -20-light strings - 6 volt bulbs -35 & 70-light strings - 3.5 volt bulbs -100-light strings - 2.5 volt bulbs -200 & 300-light strings - ES (Energy Saving HD (Heavy Duty) 2.5 volt bulbs Every manufacturer makes their own mini light bases, so the one you buy might not fit. If it doesn't, you can pull the bulb out of the base from the ones that you purchased and install it on the ones that you have.

[@vincentolivieri9561]

Thanks! Saved me a bunch of time and a headache! Merry Christmas!

[@Dr.Pepperdave]

Unless u turn it around, then in that case it will be the first one. HaHa!

[@fergy0890]

Awesome video been messin with these lights for awhile watched this video done in 5 minutes. Thankyou sir

[@eddellow4285]

Excellent video. I did not know there was such a thing as a Non-Contact Voltage Tester. I can see that being useful for all kinds of situations, specifically safety.

[@GadgetReboot]

Yes that noncontact tester is good for doublechecking live wiring in general to make sure everything is turned off or unplugged or the breaker is off.

[@ericl8743]

It only works for ac wires since ac induces a magnetic field whereas DC does not

[@TomCheer9]

@@ericl8743 Yes Eric - only the legendary velociraptor can detect a DC voltage!

[@Jeep4Wrk]

This will be so helpful! I have a couple of those testers, but never thought to use it this way. Thanks!!

[@drreason2927]

Thats great. I have a voltage tester but never thought of this. Thanks!

[@latashawalker49]

I'm here for the comments...I threw my bulbs into 2029 I'll meet them there...

[@willmarona4188]

Thank you1. Just saved me a “shed” load of time.

[@avadeal345]

The easiest simplest way I have ever seen this done. Thank you.

[@ACommenterOnYouTube]

Learn something new everyday. Simple crap like this makes you wonder why you didnt think about it.

[@Another_Random_Dave]

Worked for me lol. Thanks I’m a holiday Hero over here👍🏾

[@MrMarkpeggy]

Thank you so much for your your video! It really helps!

[@ashokm4845]

You are a good man. Thank you mentioning the binary search at the end.

[@GadgetReboot]

thanks for watching it to the end and seeing that! So many people inform me about binary search, I had to stop responding to them.

[@torq21]

An instant holiday classic! Well done.

[@johnmorneault7888]

Thanks for the idea! I'm an electrician dont know why I didn't think of it first! Haha. Merry Christmas!

[@justforever96]

You're an electrician yet you're here on KZbin looking for ways to fix your Christmas lights? Pardon me, but I'd be leery about hiring you to wire my house. Isn't a string of lights like the most basic of wiring, pure, fundamental middle school shop class wiring?

[@rupe53]

I will be doing this today. BTW, you don't need to shield things with your hand. An inch or two space between the wires is enough. Matter of fact, in most cases (depends on the tester) you can test at the tip of each bulb and that will be far enough away from the wiring. When you get "no light" you back up one bulb and retest at the wires. Saves a LOT of time.

[@MusicbyGarrettEaton]

Awesome instructions that solved my light problems. I had tried this before with a non-contact sensor, but didn't know to swap the plug to get the neutral to the extra wire. You can easily swap out bulbs from other strings and if the plugs into the sockets don't match, just bend back the contacts, pull the bulb out and put it in the original plug..

[@Dechieftian]

Thanks. Great presentation and explanation! Merry Christmas

[@007D3VIN]

Thank you for sharing, going to give this a try.

[@wayneyork6282]

Thanks , I might try this in the future !

[@BruceCurrell]

Perfect. One click, and the shunt was fixed. Great video. Thanks.

[@blakehendrix641]

Great info! Thanks for taking the time to share it and save me some money!

[@mortega561]

Wow that’s really helpful, thank you

[@jimpann]

Mission accomplished! Took me to Groundhog day to figure it out, totally missed Christmas!!!

[@GadgetReboot]

It's still only Dec 4 here...unless you missed it last year you mean...season's greetings from all of us at Acme Fast and Simple Solutions!

[@slc6900]

omg...almost 60 years later....better late than never. thanks again for showing this

[@aramistech]

Thank you for that tip, just bought the tool from the link. Makes this pretty simple to troubleshoot

[@jimb032]

Dude..you are my new hero. I was skeptical but now I'm a believer. Actually of you think about it, at the broken bulb one side will be hot from the line and the other side is referenced to neutral. Depending on how the plug is turned is the direction you will find...all hots or all neutral up until the problem. I turned the plug over so I was hitting the hots. It was a bit of a pain of you have more than one bulb thats a problem.

[@davescopes249]

I remember these kind of old stile lights years ago. Now most have a continuous live feed so if one goes out the rest still work.

[@grimreaper-qh2zn]

Exactly. Don't use the "old" sets.

[@davescopes249]

@@grimreaper-qh2zn especially if they don't work. 🤣🤣🤣🤣🤣🤣👍

[@justforever96]

These ARE the new style. The old kind are "two wire" lights, these are "three wire". And the new ones fail just the same. They are SUPPOSED to work even if a bulb blows, but that only happens if the shunt operates as it's supposed to, which it often doesn't. I have two strands of 3 wire lights right here, each with a working half and a dead half. Each one has several burnt out lights on the "working" half, yet the half works fine. But something went wrong with the OTHER half, and obviously at least one shunt is not working. So you need to go through and find the dead bulb and replace it, since that's where the shunt it.

[@trentdowler7443]

Thank you! Another great example of "Why didn't I think of that?"

[@emotivatemarketing]

Great tutorial. Learned a lot. Thank you.

[@beemanrunning977]

Excellent explanation. Thanks

[@kwlxxi4813]

Thanks for the video, very useful. A way to speed it up is check by halfs. You check first the bulb on the midle. if it works, you saved a lot of time. If doesn't work, then you go to the bulb in the 1/4 position, and so on.

[@Songwriter376]

Excellent idea.

[@zachlafond2652]

Just used this method to find 2 bad bulbs in a strand of c7 led xmas lights. Thanks.

[@philrabe910]

Brilliant! And to think I had the tool in my bags for the last 35 years! lol

[@danwebster5439]

Excellent! I have a large expensive prewired tree. Putting in a new strand would throw off the balance of light and be a pain because of the intricate wiring on each branch. I could never find the offending bulb before, but your method makes great sense. Thanks!

[@numberone7674]

on Christmas trees they are tuff. one issue I see is when taking down the tree a packing it away in the box if your not careful you can break a wire or a light bulb. Also if you notice a bulb that is burned out replace it before you cause other bulbs to burn out. Whenever a bulb goes out the voltage the other bulbs get increases a little bit and the bulbs burn a bit brighter and that can reduce bulb life

[@deanrhodenizer938]

Thanks, great video. I tried this procedure on a light set that had three sets of 50 lights. One of the three sets was working when I started. These light were embedded on an artificial tree which claimed a high number of lights, approximately 1,500 if I remember correctly. Here’s the part I didn’t know - The original bulbs had a special feature: if the filament burned out the bulb was designed to short - that is, the bulb would go out and the remaining lights in the set would stay on but now running at a slightly higher than intended voltage. This was a clever idea in most respects but after enough bulbs failed, the voltage would get too high for the remaining bulbs and a complete set failure would occur. I was following the procedure you suggested (had to go one-by-one because of being mounted on a tree) and eventually found a bulb that was opened. When I would replace this defective bulb it would flash briefly and then burn out. Eventually I was able to figure out what was going on. I then removed all the bulbs in the non-working sets and proceeded to test them using the working set, I did this by removing one bulb from the working set and using that socket to test the non-working bulbs that I had removed. I discovered maybe two bulbs that worked. I then purchased a couple of 50 bulb lighting sets. Purchasing individual 2.5V lamps was way more expensive that buying full sets of lights. Unfortunately, the socket type of the new sets did not match the socket type of the old set and I had to transfer these bulbs to the old sockets - removing the old set from the tree was just too much work. When I finished replacing bulbs the two sets that were previously not working were working… but there were still lamps that were out. It turns out that these were part of the original working set. Fortunately, not enough of them were out to make the voltage too high for the remaining bulbs so that set remained lit. I replace these bulbs and all was well.

[@GadgetReboot]

Sounds like a big Christmas adventure! I have a pre-lit tree and luckily none of the built-in lights failed yet. I think I would prefer if the bulbs did not have the built-in shunt because it just prevents us from realizing something burned out and then eventually the whole string gets blown.

[@UNITED2009100]

I think you nailed it. Sometimes we just don't see one or two that are burnt out. That puts more voltage on the ones working and pretty soon they all turn black and burn out. Replacing them all BEFORE trying to light the string is smart and perhaps the only way to keep the new ones from flashing and going out. Once the string is on the tree, the job becomes very difficult. Thanks for your suggestion.

[@marinvidovic763]

Sounds like a "A Post Apocaliptic inventor" gave you some incentive to do all this. Go and watch his y.t channel. He is unbelievable. All the best.

[@darinabstonjr9512]

Damn I pray you got your Christmas Gift...

[@Go1US1Marines]

Thanks. Worked like a charm. One side note: my tester wasn't working. I removed the battery cover and found that the two button batteries had slightly oxidized surfaces. I burnished them with the edge of a utility knife until they shined, popped them back in, and it is now working like new. Also, a quick visual inspection of the string, bulb by bulb will sometimes identify the culprit. Burn outs have a telltale grayish opaque coating on the inside of the bulb.

[@Cycle774]

Best explanation I’ve seen! Thank you!

[@larrrevenga49]

Simple & great info . I’m 40 year retired construction trade electrician . Got pretty far trying find easy way . But not realizing non polarized plug AND using hand for shield . I was getting no where fast . I did figure out the two series loop in the wiring 😂 thanks for the tip ⚡️

[@larrrevenga49]

I just want to add on OLD light sets other then lamps .OTHER wiring problems do exist from broken conductors to loose connections in socket . Just buy & use C-9 paralleled wired or as they call it stay lit Xmas light sets

[@0623kaboom]

youre an electrician ... what happens to a filament bulb when the filament burns out ... it gets sooty ... look for that ... BASIC electronics ... you should have learned that day 1 ... if not by the time you were 6 years old ..

[@0623kaboom]

@@larrrevenga49 or dont and use your eyes to find the burnt bulb and stop trashing perfectly good strings because your too lazy to spend 10 minutes checking out 10 strings of lights by eye .. and just add more waste to the garbage pile ... economize recycle reuse it aint garbage until its covering is compromised or the plug is broken or the wire ... costs less saves more and lowers the cost of future lights because we aint tossing out a perfectly good set because one bulb fried its filament ...

[@larrrevenga49]

@@0623kaboom I save them from going into the garbage by only buying C -9 I have the same sets for 20 years

[@larrrevenga49]

@@0623kaboom Very funny by 6 yrs old Yes my eyes were very good at 6 yrs old not so much now Save your self the aggravation And keep landfills empty by buying C-9 lamps I have only used C-9 & they look better

[@ginnymiller2448]

Thank you for this video, it was very helpful! I have a set of "globe lights" on my RV. Went outside this evening to discover half of them not lit. I **really** didn't want to crawl around under my trailer taking each of the lights apart, since removing the plastic globe housings around the lights is an additional step to an already tedious problem. Found the bad bulb and replaced it in a jiffy!

[@GadgetReboot]

I'm glad it was helpful, especially saving on the struggle with that situation.

[@josephpk4878]

This helped me to save an outdoor spiral X-Mas tree that my wife was about to toss out. I took my current tester (get one - they're a go-to electrical tool) and some tin foil dummy bulbs, then walked my way up from the plug-end until the entire run lit up. This strand has 3 tap-in points, and I only had to test 2 of them to get it all lit up. Because all if the bulbs are zap-strapped down onto the spiral/coil framework, I didn't want to cut everything off to be able to isolate the bad bulbs, so I just followed the hot wire and pulled it out, just enough to get my thumb under it - this was enough to isolate the other wires from the tester. The tin foil plugs were just a temporary means to diagnosing the strand - they required some shaping and wiggling to make a good contact - you know the contact is good when you get the output wire to indicate current. Thanks for the tips! ... and Merry XMas.

[@pnkrkz]

Dude, without this video, I would have been wringing my head on trying to find a bad bulb. It turned out I had two bulbs that had their leads broken, so could do process of elimination if just doing a visual check. Using the handy dandy Harbor Freight probe did the trick! Thanks again for posting this!

[@GadgetReboot]

There are now follow up videos kzbin.info/www/bejne/anvbiYCiqq13l8U kzbin.info/www/bejne/nHOYoGB5hMmrl5Y If you'd rather just buy new lights, here's an affiliate shopping link: Amazon.com: amzn.to/3Ai6qme Amazon.ca: amzn.to/3X6i8dw

[@briytinbym]

Correct! I thought the same thing - half the circuit. Much faster when isolating.

[@mpmarvin999]

That’s what I was thinking all the way to 5:30. “Come on electric light bulb genius guy. You gonna have people check each light.... “ 5:30 “.... ah there we go! Great video”

[@BobMuir100]

Thanks again but I have all LED’s now as got feed up with old stuff. But if not I would have taken up the offer however in England so always need to take code to .co.Uk site, do you guys still get your commission? I would like you too. Interested in that test pen thingy

[@GadgetReboot]

I would have to set up a uk amazon account but wasn't sure if there'd be any interest from viewers. I'll think about it for the future. Thanks for watching either way!

[@BobMuir100]

@@GadgetReboot : I will I enjoyed your work. Thank you

[@sethfitzgerald425]

Thank you so much sir! I was so annoyed after half of my strands of lights were only half lit AND the fuses had continuity with no visual issues of the bulbs. I greatly appreciate your shared knowledge and my wife will love to keep these pepermint colored lights around for awhile longer! God Bless and Merry Christmas!!

[@FredMiller]

Nicely done!

[@markej4801]

Think I'll be getting this bit of kit soon. I hate trying to track down bad Christmas light bulbs.

[@AnotherMaker]

This is very cool. Thanks for showing us a truly idiot-proof way of fixing these. I wish I would have thought of this.

[@GadgetReboot]

Glad to be of help! It's so fast and simple and saves time and money, can't go wrong!

[@lanceparker2190]

Thanks for the video. I forgot I had a tester like this. I found I didn't have a burned out light but one that the wires came off of but was still stuck to the string.

[@deanverhoeven]

Worked for me. Thanks, good clear explanation.

[@dusttodusthomestead]

Wow. Helpful tip......I'll probably need to use this within the next week or so. 👍

[@bobjohnson4213]

AWESOME!!

[@fathernojoy2706]

I wish I knew this 10 years ago, before I threw everything out and converted to LED!! Could have retired by now with the savings LOL.

[@rickcurtis2983]

Great demo, thanks!

[@Stealthypanda208]

Thanks for the video! It will save me a lot of time! Very well explained.

[@zmanpianoman]

I love it when they test good on the floor then crap out after they are hung on the outside gutters. Thats why I now use lasers stuck in the grass. Lol