Greetings.
I'm looking for some suggestions to avoid strip failure problems that I had last holiday season. Any suggestions about why I had such a bad experience and how to avoid it again would be welcome.
Last Christmas (2015) I added a 12 strip mega tree to my display. Advance testing went well, as did initial installation. So I started the season with a working mega tree. But then the strips started to fail. At first just the upper part of one strip. Then another. And another. After a month, all 12 were in various states of full or partial failure. After taking it all down, I tested the strips in warm conditions, and 2 of them worked again, but not the rest.
The common symptom is that part way up the strip the voltage goes funny. These are 5v strips and it can be the data line or the +5 line that shows wrong voltage. (I test the voltage by poking a probe through the silicon sheath - only after taking them down.) Typically the data line shows a constant high voltage above an LED and normal voltage below (a very small fluctuating voltage is what my tester shows for an operating data line). So I'm guessing that the LED failed and is shorting the data line and breaking everything from there on.
Visually, the LEDs work fine up to a point, and then beyond that they are either out or 1 solid colour. And they aren't all the same past the "break point", so some my be out some one colour, some another. And turning power of and on can change the colour above the break point.
I bought 3 of these strips in 2014 and had no problem with them. One of those 2014 strips was wrapped spirally around my light post in the front yard, very exposed to winter weather and worked throughout both winters (as a static light strip after the holiday season). So I thought they'd be a good choice for the mega tree too.
These are the strips I used: http://www.aliexpress.com/store/product/BLACK-PCB-5m-DC5V-WS2812B-led-pixel-srip-IP68-30pcs-WS2812B-M-with-30pixels-reverse-protection/701799_926778326.html
I replaced the stock connectors with Ray's pigtails.
There was no obvious signs of water inside the strip sheath when I took them down.
Weather was odd last year. Very mild up to Christmas Eve, then turning back to normal (sub-zero C all day). No failures before Christmas Day, but by New Years about a third were failing. Some rain before Christmas and some snow after. I don't think anything would have warmed up enough to melt the snow up to New Year's Day, so I'm having a hard time believing water got in. That said, the silicone filler at the end of the strip looks much more robust on the 2014 strips than on the 2015 ones. But at IP68, I wouldn't expect all 12 to suffer water intrusion.
So what do you think? I appreciate any input.
I'm looking for some suggestions to avoid strip failure problems that I had last holiday season. Any suggestions about why I had such a bad experience and how to avoid it again would be welcome.
Last Christmas (2015) I added a 12 strip mega tree to my display. Advance testing went well, as did initial installation. So I started the season with a working mega tree. But then the strips started to fail. At first just the upper part of one strip. Then another. And another. After a month, all 12 were in various states of full or partial failure. After taking it all down, I tested the strips in warm conditions, and 2 of them worked again, but not the rest.
The common symptom is that part way up the strip the voltage goes funny. These are 5v strips and it can be the data line or the +5 line that shows wrong voltage. (I test the voltage by poking a probe through the silicon sheath - only after taking them down.) Typically the data line shows a constant high voltage above an LED and normal voltage below (a very small fluctuating voltage is what my tester shows for an operating data line). So I'm guessing that the LED failed and is shorting the data line and breaking everything from there on.
Visually, the LEDs work fine up to a point, and then beyond that they are either out or 1 solid colour. And they aren't all the same past the "break point", so some my be out some one colour, some another. And turning power of and on can change the colour above the break point.
I bought 3 of these strips in 2014 and had no problem with them. One of those 2014 strips was wrapped spirally around my light post in the front yard, very exposed to winter weather and worked throughout both winters (as a static light strip after the holiday season). So I thought they'd be a good choice for the mega tree too.
These are the strips I used: http://www.aliexpress.com/store/product/BLACK-PCB-5m-DC5V-WS2812B-led-pixel-srip-IP68-30pcs-WS2812B-M-with-30pixels-reverse-protection/701799_926778326.html
I replaced the stock connectors with Ray's pigtails.
There was no obvious signs of water inside the strip sheath when I took them down.
Weather was odd last year. Very mild up to Christmas Eve, then turning back to normal (sub-zero C all day). No failures before Christmas Day, but by New Years about a third were failing. Some rain before Christmas and some snow after. I don't think anything would have warmed up enough to melt the snow up to New Year's Day, so I'm having a hard time believing water got in. That said, the silicone filler at the end of the strip looks much more robust on the 2014 strips than on the 2015 ones. But at IP68, I wouldn't expect all 12 to suffer water intrusion.
So what do you think? I appreciate any input.