I’ve got a string of 5 WS2812 rings and sometimes a particular LED will stop transferring data out (but will still change its own brightness setting as expected). I’ve verified with a scope that it’s not outputting any data when in this state so I can rule out any signal integrity issues. When I first turn the strip on everything works as expected, but after some time this LED goes wonky and every LED downstream of it stays stuck. Sometimes it starts working again on its own but usually not. The issue seems to get worse at higher brightness - ~75% generally locks up in a few minutes but ~40% stayed running for an hour without issue.
like all tiny electronics, heck, all electronics in general, there is a certain failure rate… and with LEDs, you’ll see partial failures like this at times. Often it’s visible (light doesn’t light), but in this case, it’s the output. It’s a defective LED, and likely it’s only going to get worse. Could be heat related, as when you increase the power, there is no question it’ll get warmer, and that could be it.
I’d say replace the ring. Depending on the source vendor, you might want to see if they’ll just replace it, but at that price, I’d just buy a handful of spares anyway.
My guess is it’s a broken wire/connection inside the pixel, that is still making contact when it’s cold, but as it heats up the plastic package expands a little, enough to sever contact. I’ve had them fail in strips where it’s easy to cut out the bad one and solder in another, but that’s probably not an option in the ring.
Just got the ring replaced and haven’t seen a failure in ~5 minutes. I could definitely desolder and replace the bad pixel in a pinch (or scavenge the good ones off it if I need one for something else) so I’ll hang onto it for now. Thanks again for the insight y’all!