WTF is with these berkeleying things? Both fuses are good, yet half the string doesn't light. Yeah, I know I can get another string for $5, but that's not the point. I hate throwing these things in the trash when half the string still works. There's got to be a reasonable way to troubleshoot and repair these things. Help me, GRM!
Cut it at the point it doesn't work and then you have a full string that works.
In reply to AngryCorvair (Forum Supporter) :
One of the bulbs is either loose in the socket or burned out. Sometimes you get lucky and can see the defect, you would need a replacement bulb obviously. I started switching over to LED a few years ago and they seem to last longer so far.
We'll find out shortly if I just cursed myself as my beloved bride has been pulling the Christmas boxes out of storage and it's my job to put the lights on the tree this afternoon. 
I've spent a fair amount of time reading about and trying various techniques to repair strings of lights. All that time has been wasted. Throw the darned things out!
Edit: Unless a quick visual inspection reveals a bulb that is broken or missing, in which case replacing it should restore the string.
I have a couple of LED strings that have little controllers that make them blink or fade in and out. The controllers have a short lifespan, less that one season. You can plug them straight into the power supply but only half the string (every second light) illuminates. The other half is on the other polarity.
So I built a little controller that alternates polarity at a frequency I choose. Used an Adafruit Trinket and an H bridge. It's been working for several years.
I have maybe 5-6 sets of nice LED christmas lights that half work or dont work. They have a resistor up front and one halfway through. I have some resistors on the way to try and repair them.
prowlerjc said:Light Keeper Pro works great. Amazon has them.
Quoted to get more attention. We're not a fan of LEDs in the tree, and this thing is the only thing that keeps me from jumping off a cliff...
prowlerjc said:Light Keeper Pro works great. Amazon has them.
My BIL is an electrician and he swears by that thing.
I had 65' or so of red/orange/green/blue led lights in my living room that we use as mood lighting for watching tv so they have gotten a lot of hours on them in just a few years. Suddenly two quarter sections of lights dimmed and then went dark. These are "if one light burns out, the rest stay lit" but that was a lie.
Our Christmas tree gets put in a corner with the dark side facing the wall. I gave up trying to find the fault.
Another vote for Light Keeper Pro.
https://www.acehardware.com/departments/home-and-decor/holiday/christmas-indoor-decor/9884750
berkeley, I used to have one of those. Maybe I still do.
I've fixed lots with the removable LED bulb holders (the push in style). Mostly it's one of the led leads has corroded and broken, taking out that portion of the string. Take the bulb holder out, check the leads, put it back until you find the source of the issue. Every once and a while you'll need to wiggle the leads to find the one that's broken. It's a pain, but better than buying new sets every year.
Light Keeper Pro is the tool if you want to spend the next forever fixing lights. Works great until you waste your life fixing every broken strand you come across just to save $2.50 on a new 100 light set.
In reply to AngryCorvair (Forum Supporter) :
If you have the extra time on your hands and the lights in question are incandescent, you can use the bulbs as DIY model rocket ignitors. Then you get to see things light up, smoke and fly off in to the unknown.
stafford1500 said:In reply to AngryCorvair (Forum Supporter) :
If you have the extra time on your hands and the lights in question are incandescent, you can use the bulbs as DIY model rocket ignitors. Then you get to see things light up, smoke and fly off in to the unknown.
I'm intrigued by this idea. 
I have tired a few times to get a string of lights working again and have decided its not worth the time. We are moving over to all LED lights since they seem to have a longer life than the incandescent ones.
If you are going to buy new lights, stop buying pre-made garbage from Lowes or Target or <insert store>. Order from an xmas light supplier and you can make exactly the strand length/type you need out of higher quality stuff. Very repairable as well.
Spoken from someone who got rid of all his lights, and even his house. None of that bullE36 M3 to deal with at my apartment :)
I had a string of LED lights let me down yesterday. Tested them inside, put them in some shrubs and the did not light up.
Tested the extension cord, Tested the outlet, got out a multimeter and tested the fuses in the string of lights. I Tested the continuity in the string of lights and there was no continuity. I then unraveled the sting from the shrub and took them inside and plugged them in. No lights. I then threw them away and got out a set of old time lights I had with the big bulbs. Plugged those in, replace a few bulbs and into the shrub they went.
And no I did NOT save the fuses from the bad string of lights. But I did think about it.
We've had good success with older LED's that have molded in bulbs. The replaceable bulb ones are more susceptible to water getting in and have many more failures. I'm cheap so I'd rather fix the string than get a new one that'll fail again just as quickly. Our next purchase will be a more professional level setup, with cut to length strings and screw in bulbs. If you can keep the lights under the roof line of your house, away from water, they'll last much longer.
You'll need to log in to post.
