I have an outdoor LED light chain, which consists of two parts.

This morning when I got up the second part of the LED chain had begun glowing very faintly (see image). The first part of the chain (which is nearest to the plug) is fine. None of the bulbs are dead (as far as I can tell)

I checked the plug connecting the two parts and it looks dry. I measured the voltage across the plug and found 220 volts.

Does anyone know what is going on? And, more importantly, can this be repaired?

LED strands installed, near strand works fine, far strand is dim

The product is from Amazon: https://www.amazon.co.uk/Festive-Lights-ConnectPro-Outdoor-Festoons/dp/B06ZY6PFSY

The lamps are wired from the mains to a transformer of sorts. There is no information on the transformer (or whatever the thing is). There is a label on the on the cabel itself that reads: Lamp spec. 10 buldbs (LED) per 3V, max 20mA. The plug that connects the two segments has two prongs. Everthing is connected to 220V mains. I measured 220V on the plug that connects the two segments.

Below is a picture of the plug the LED chain uses.

Mains plug with cord to unknown box, cord from that to receptacle for LED strand

EDIT No. 2: Below is a photo of the connector that connects the two strands of lights.

The bulbs are sadly integrated so I cannot remove them from their sockets.

Connector that connects the two strands of lights

EDIT No. 3: I tried swapping out the strands and as expected the dim strand still didn't work. My old man then suggested I leave the defect strand in the boiler room overnight to 'dry out'. I did that and then it worked again. When I hung the strand again I could see water inside two of the bulbs. Many thanks to all that replied to my question!

  • We would need a lot more detail than you've provided here, if there's to be a diagnosis from afar. Please provide at a minimum information about the exact manufacturer and model of lights, the exact configuration of the wiring, and whether the bulbs have integrated drivers or the string has a separate LED driver or drivers. Jan 3, 2021 at 19:07
  • My apologies @PeterDuniho and thanks for replying. The lights are similar to these: amazon.co.uk/Festive-Lights-ConnectPro-Outdoor-Festoons/dp/… I measured the voltage in the junction between the two sets of lights and measured 220v which makes me believe the bulbs must have integrated drivers. The lights are writed from the mains -> "starter plug". Let me know if you need more info.
    – chris-k1
    Jan 3, 2021 at 19:22
  • Comments are for other users to request clarification. Please use the edit link to respond to requests, by including the needed information in the question itself, not as a comment. Also, I don't know what "lights are writed from the mains -> "starter plug"" is supposed to mean. I assume you mean "wired" and not "writed", but what's a "starter plug"? Some clear photos of the actual wiring would help. Jan 3, 2021 at 19:34
  • 1
    A photo of your actual light string instead of an Amazon link to "something like this" would be most helpful. If the ones you've linked to are different in any way, advice may only work for that one, not yours. Also, there appears to be something on the light cable between the 5th & 6th bulbs (starting from the right) - maybe include a close up of that one, including any writing on it.
    – FreeMan
    Jan 3, 2021 at 20:03
  • 1
    I appreciate that, but of course first and foremost on Stack Exchange sites is to ensure the information is as useful and immediately findable as possible. Accepting your own answer achieves that goal. Indeed, while I understand many people view the voting buttons as transactional, I agree with the original philosophy of SE that actions like voting and accepting answers are primarily to provide information to future readers. The reputation point system is secondary to that. Anyway, welcome to the site. :) Jan 8, 2021 at 7:46

2 Answers 2


With the help from Peter Duniho I tried reversing the strands and found that the problem persisted. My dad then suggested I put the defective strand in the boiler room to dry it out in case water had gotten in the circuit.

I left the strand for 30 hours and tried it again and it worked! When I hung the chain again I could see water in two of the bulbs.

Many thanks to the people that provided helpful suggestions!


I'm afraid that with the details so far, I personally can't say exactly what's wrong. That said…you can do some more testing to better characterize the problem, and I believe that testing will give you the answer you need (unfortunately, in neither case is it likely that it will be something you can literally fix yourself, unless you're an experienced electrician or electrical engineer).

Looking at the Amazon page, it appears that:

  1. A "starter plug" is just the extension that connects the light strand itself to the mains outlet;
  2. The bulbs are integrated into the sockets of the strand and are not removable.

Based on that, since you have two strands, one diagnostic step you can take is to swap the two strands for each other.

My guess is that after the swap, just one strand will still not be working correctly, and it probably will be the same strand that's not working now; there's a small possibility after the swap both strands won't work. Either way, that'd be sufficient evidence for me to consider the one strand that's not working now to be defective; you should just send it back to the manufacturer for a replacement.

If after the test, the problem moves to the other strand, i.e. it's still the second strand in the series that's not working even though that's physically the strand that was fine before when it was the first strand in the series, then I guess it's possible there's an electrical problem with the outlet. What kind of problem exactly, I couldn't say.

You could verify or refute the possibility of a problem with the outlet by testing the two strands together in a different outlet. Be sure to use a completely different circuit, not just a different outlet on the same circuit. If the lights work fine on a different circuit, you can go back and test the lights in a different outlet on the original circuit to differentiate between a problem with the circuit overall and a problem just with that one outlet (I reckon the latter is more likely, but it's best to figure out for sure).

I think a problem with the outlet or circuit is highly unlikely. But if it turns out to be that, then you'll need an electrician to help fix it.

I expect you'll find that it's the lights themselves that are defective though.

  • Thank you Peter for your help! I will try and swap the strands out (why didn't I think of that!). It is pouring down here tonight so I'll do that tomorrow. Thanks again for your help!
    – chris-k1
    Jan 3, 2021 at 20:13
  • @chris-k1: consider waiting until tomorrow to accept my answer, or any other you might receive. For two reasons: 1) that'll give you a chance to actually try some of my suggestions, and 2) if you accept the answer now you might get fewer other people taking a look at the question. You may benefit from the perspective of more than one other person! :) Jan 3, 2021 at 20:24
  • @chris-k1: (note that you can click the checkmark again to "unaccept" the answer, if you like) Jan 3, 2021 at 21:07
  • Cheers - I am still getting used to platform.
    – chris-k1
    Jan 3, 2021 at 21:14

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