5V WS2811 Pixels Being Faulty Again

[Lucas H]

Hello everyone, some of the pixel computer chips inside of pixels are burnt a little bit which seems to be causing them to stuff up and is just something bad in general.
The light show is running at 30% brightness with power injection ever 200 - 250 pixels.
A lot of the pixels have seemed to stuff up in one year since I only got them last year. They were only up around Christmas time last year and have been put up again this year a few weeks ago and now there is a problem with them.
Some pixels seem to have faulty colour issues, so we've replaced some of those individual pixels so far, with left over with the few pixel strands from last year. Some pixels also seemed to be not letting the data through, so we've had to replace those individual pixels as well. We still have a fair few strands to fix up still.
All the pixels in the mega tree star were replaced yesterday because there were too many faulty pixels for it, now one of the pixels was already staying on blue when plugged in sometimes.

Does anyone have any advice to help me out here?

 

[AAH]

Can you post some more pictures of other pixels and also show the other side.
Where that is showing as being "burnt" isn't where I would expect that there's high current that is likely to cause burning. The discoloured area is where the red and blue legs of the pixel leds get soldered to the pcb. If this spot is a common failure point it may be due to the soldering process which is why I'd like to see what the other side of the pixels look like.
Can you check that your 5V supply is putting out close to 5V. The blue pixel problem is often seen when voltage is too high coming from the power supply.

 

[Lucas H]

Can you post some more pictures of other pixels and also show the other side.
Where that is showing as being "burnt" isn't where I would expect that there's high current that is likely to cause burning. The discoloured area is where the red and blue legs of the pixel leds get soldered to the pcb. If this spot is a common failure point it may be due to the soldering process which is why I'd like to see what the other side of the pixels look like.
Can you check that your 5V supply is putting out close to 5V. The blue pixel problem is often seen when voltage is too high coming from the power supply.

I will check the voltage for the power supply as soon as I can.

When you say that I need to post more pictures of other pixels, do you mean the ones that are still in the props or the ones that have been cut out of a strand?


Here is the photo of the other side of the burnt pixel.

 

[AAH]

The more photos of faulty ones the betterer.
That pic isn't the greatest but that does look like there is a brown line around the leads of the led which looks like it's a dry joint. It's probably a bit hard getting a good pic through textured pvc and then epoxy.

 

[Notenoughlights]

Is it burnt, or rusted out, has water gotten down inside the front through the resin to below the LED?

It looks like rust to me, as below the "burnt" part, appears to be staining not of the colour you would expect if it was burnt.

 

[Lucas H]

The more photos of faulty ones the betterer.
That pic isn't the greatest but that does look like there is a brown line around the leads of the led which looks like it's a dry joint. It's probably a bit hard getting a good pic through textured pvc and then epoxy.

Okay.

 

[Lucas H]

Is it burnt, or rusted out, has water gotten down inside the front through the resin to below the LED?

It looks like rust to me, as below the "burnt" part, appears to be staining not of the colour you would expect if it was burnt.

I don’t think there has been any water that’s gotten in there though so I don’t know how it could be rust.

 

[AAH]

Is it burnt, or rusted out, has water gotten down inside the front through the resin to below the LED?

It looks like rust to me, as below the "burnt" part, appears to be staining not of the colour you would expect if it was burnt.

There is another failure mode which is the flux from the solder which when exposed to sunlight will break down and go from generally being quite clear to yellow, brown and even fairly black.

 

[Kartman]

I feel your pain. Last year I tested all my props before putting them up and all tested OK, but once up the megatree started having weird failures. I would replace faulty pixels and the problem would just move on. I ended up getting all new pixels for @AAH and haven't even had one failure on the Megatree since.

This year I started getting some weird faults on other props with pixels of the same vintage. Random strobing of pixels, the blue locked on pixels you talked about etc etc. Tried replacing faulty pixels and the problem just occurred somewhere else. So I bit the bullet (pun intended) and bought another batch of pixels from @AAH and each time I get a prop playing up I replace all the pixels with new ones. Touch wood, a few hundred pixels later and no more issues, and it has been hot humid and monsoonal. Although the star on top of the megatree has a blue pixel so it may need to come down.

I have other props with pixels from same manufacturer but bought at a different time and not one failure in a couple of years.

After discussion with @AAH my thoughts are that I live in Cairns and the heat and humidity is stressing the waterproofing / epxoy and causing it to fail. While I was waiting for the new pixels to arrive we had a week of hot and dry weather and the problems lessened, but as soon as it rained the failures came back, so that's a bit of confirmation bias.

I am not sure the blue stuck on pixels are a voltage problem in this case. I use 5v and have checked the power supply and it is 5V and pixels are / were stuck on blue at points in strings away from the power injection, so voltage would be below 5V.

My thoughts are it is just a bit of bad luck that we got some 'dodgy' pixels.

 

[Lucas H]

I feel your pain. Last year I tested all my props before putting them up and all tested OK, but once up the megatree started having weird failures. I would replace faulty pixels and the problem would just move on. I ended up getting all new pixels for @AAH and haven't even had one failure on the Megatree since.

This year I started getting some weird faults on other props with pixels of the same vintage. Random strobing of pixels, the blue locked on pixels you talked about etc etc. Tried replacing faulty pixels and the problem just occurred somewhere else. So I bit the bullet (pun intended) and bought another batch of pixels from @AAH and each time I get a prop playing up I replace all the pixels with new ones. Touch wood, a few hundred pixels later and no more issues, and it has been hot humid and monsoonal. Although the star on top of the megatree has a blue pixel so it may need to come down.

I have other props with pixels from same manufacturer but bought at a different time and not one failure in a couple of years.

After discussion with @AAH my thoughts are that I live in Cairns and the heat and humidity is stressing the waterproofing / epxoy and causing it to fail. While I was waiting for the new pixels to arrive we had a week of hot and dry weather and the problems lessened, but as soon as it rained the failures came back, so that's a bit of confirmation bias.

I am not sure the blue stuck on pixels are a voltage problem in this case. I use 5v and have checked the power supply and it is 5V and pixels are / were stuck on blue at points in strings away from the power injection, so voltage would be below 5V.

My thoughts are it is just a bit of bad luck that we got some 'dodgy' pixels.

Yep I live in the Ingham district, I have a lot of humidity and rain and stuff like that as well

The pixels that we bought last year was from LightItupLeds.
The mega tree has pixels from Advatek and have been working perfectly fine for the past 2 years or so.
My dad bought some Advatek pixels in about 2014 and they were running for a while as well.

I’ll still try to check the voltage on the power supply just in case, but I can’t at the moment because the lights are at our other house.