Sudden signal(?) problem "for no reason" POSSIBLY SOMEWHAT SOLVED I installed LED strips on

Sudden signal(?) problem “for no reason”


I installed LED strips on the outside of my house and part of the garage. All the strips were working fine. I had to put things on hold for a while. When I turned everything on today – in anticipation of adding more strips – most of the strips on the house acted up. The ones on the garage work perfectly. I tried to take a video, but even the working LEDs look like they’re blinking on the video (not sure why).

WS2812Bs, running off an Arduino Mega 2560. LEDs have their own power (not running off of the Arduino VIN).

The lights giving me trouble have a long run from the Arduino, but the two signal wires are twisted pairs with grounds hooked up. Power is 12V, stepped down 4.6V just before the strips. I don’t think it’s the setup as everything worked perfectly before.

The two strips in question are in an inverted V in the gable of the house. Each receives a signal at the top and the pattern is mirrored (and the same thing is happening in the garage gable – except it’s working there). The first dozen or so pixels on one strip respond fine and then I get random blinking or nothing on the rest of the strip. The second strip is doing the same thing, but a few more pixels respond properly.

The sketch is a simple one. It fills in Red, one pixel at a time. Then it does the same thing with Green, then Blue, then White, and repeats.

I’ve tried a different Arduino running a different sketch and it made no difference.

Again, everything worked perfectly before, and I can’t think of a thing I might have changed.

Worst case scenario – no Christmas lights this year and try rewiring next year when it gets warmer.

Best case scenario – someone suggests a solution that works. :slight_smile:

I’m open to ANY thoughts or suggestions.

Could the wet have gotten in to them as first thought or connecting’s corroded

Sorry to hear that. Always frustrating when things were working and then suddenly aren’t.
If possible check the voltage levels where ever you can. That will be a start.
Wiggle/press on connection points/solder joints to maybe find a connection that is going bad.

@dave_windsor I doubt it’s moisture. I really sealed things well.
@marmil First thing I did was a lot of unplugging, re-plugging. Tends to be the way I address MOST problems (good thing I’m not in charge of people on life support).

If I have time, I’m going to build some extra long “jumper” cables that I can run from the Arduino and power supply up to the strips. I’ll see if by-passing the existing wiring solves anything.

Thanks for the thoughts so far!

I’m always open to more!

I got up on a ladder and swapped the two power and signal plugs for the two strips. The problems remained in the same position on each strip (instead of “moving with the connection”).

I pressed down on the first flaky LED on one strip and the rest of the strip started working.

Looks like a bad LED on each strip is causing the problem. In hindsight, one of the reels of the ten I ordered had some dead spots that I thought I eliminated by choosing working chunks of the reel. Now I’m thinking that whole reel had some faulty soldering or similar. The drop in temperature between the two latest installation session was probably enough to make the strip or connection contract.

Good news is that I made the strip sections modular and removable, so I should be repair it and do it indoors, an I won’t have to make and run hundreds of feet of new power/signal wire.

Bad news is that even if I fix it, the lights will be up a little late for the season, and it’s a gettin’ cold to be working outside! :slight_smile:

I’ll confirm the repair if/when it’s up and running again.

Glad you got it figured out. I’m planning a similar power set up for some of my strands. Still waiting for step down buck converters to come in. Did you use a fuse with them as well? I read somewhere that it was wise in case the buck converter fails, but I’ve never dealt with fuses and don’t really feel like starting now :slight_smile:

How early do people decorate where you are?

looks like you got a solder problem just like me in the past.
If this is the case there is no quick fix unless you are willing to swap them out. Sorry to hear that, man.

@Charity_Stolarz I didn’t fuse the buck converters, but I did add schottky diodes – one on each of the the negative inputs, to prevent problems if I accidentally reversed the polarity going in, and one on each of the positive outputs to prevent and “backward” flow of power if the converter fails (unlikely since I isolated all the power supplies from each other, but better safe than sorry).

The “start” of Christmas decorating varies widely out here. Typically, people wait until after Remembrance Day, but you can sometimes see the odd tree lit up indoors Nov 1!.

Quick update. Did some surgery on the two strips and replaced the dodgy LEDs. One strip works perfectly now – the other revealed two MORE bad LEDs. Back to surgery last night, and including a third strip from further down the line with a bad LED. Hoping to install them tonight – though I’m feeling under the weather this morning, so who knows.

I know I keep belaboring the point – but building this system with removable, modular parts was probably the best project decision I’ve made in a long time!

The funny thing is, overall I enjoy the process – even fixing faulty product – it’s just the self-imposed deadline that makes it frustrating. Weird what we’ll do to ourselves. :wink:

Another quick update. After replacing bad LEDs twice on each of the problem strips, more showed up. Time to strip everything from that reel off the J-trim and replace with LEDs from a different reel.

It’s only a hobby. It’s only a hobby. It’s only a hobby. It’s only a hobby.

keep your head up i seen David Blaine speak a couple years ago “distinguished speaker series” and he said really in a nut shell whatever you chose to do you need to enjoy the path or Rather the BUMPING YOUR HEAD try to look at the troubles your running into as the chance to learn i bet any money you have learned more by trouble shooting etc than if it had just worked the first time believe me i know most everything i take on is 99.9 percent bumping my head it comes from our ambitious ways to do this stuff at all is amazing when we stand back and look from a different stance oh and i was just thinking i had ran some leds in my PC case and had issues ended up using RCA cable thinking the shielding helped maybe experiment with that? idk its all trial and error good luck and happy holidays

I don’t have all the strips mounted, or enough patterns for my taste but the lights are up and running!

Of course, that’s AFTER one of my eBay buck converters failed and I had to replace it. :slight_smile:

Just keeping my fingers crossed to see what happens as the temperature drops. Right now we’re having very unseasonably warm weather.

Take care all!