Problems with Addressable strips Failing

Other Hardware LEDs and Multiplexing
1

Hi All,
Hoping someone might be able to work out what's going on with my install...

Back Story
3-4 yrs ago I installed appx 9m of RGBW Led strip (60LED/m of WS2812 flavour) along the underside (soffit) of the front of my house. Whilst 95% of the time the lights are set for plain white at 30% pwr, the colours were used at Christmas/Halloween etc.
Halloween

The early strip was the IP65 version where the led side of the tape has the silicon extruded covering, where I spliced on extra power feed along the length or joined the 2x 5m tapes I protected the area with PCB lacquer sprayed on.
The first strip lasted about a year, then come autumn/winter it stopped working fully, would only light the first 1.5m or so and the rest of the strip was off. To start with I found if I pressed on the first unlit LED, the rest of the strip would light. I presumed there was corrosion getting into the strip or a faulty LED and so cut the strip at that point, removed a LED or so and reconnected.
I had to do this 2 or 3 times before I got annoyed and decided to start over.

So just over a year ago I bought 10m (2x5m) of RGBWW LED strip (60LED/m SK6812 flavour) but this time the IP67 version, which is the strip inserted into a silicon tube and sealed at the ends. More a pain to stick up, but hoped it would remove moisture from the equation. Now the strip is powered from each end and a centre tapping, but as I don't need to run the strip at full current/load wont be an issue.

Now
So a couple of days ago, I noticed that when the system turned on (the PSU and Arduino are switched via a timer) I'm back to only having light on the first 2m or so, the LEDs stop working around LED 130ish.
Again I managed to get the rest of the strip to light by pressing up on the first unlit LED for 2x nights, but tried tonight and it doesn't want to go.
Photo 1

Photo 2

So...
Originally, given the way it always failed around the same area - I thought it was an electrical issue, but then the ability to get it working by pressing the LED made it a physical problem.
As said I thought moisture played a part even though it looked OK, but now with the IP67 version (not that i expect the Chinese rating to be fully accurate - but it is reasonably sheltered) it shouldn't matter.
The strip is affixed to the plastic soffits with adhesive fixing tape, the soffit does deflect slightly but IS secure and doesn't otherwise move. The soffit is a Tongue and groove profile, so the strip isn't in contact 100% along the way, but again I don't see any real movement at the 'grooves'.

Can anyone suggest what the hell is going on? Why do I keep having this issue and approximately in the same area?

Edit : Couldn't get pics to show

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Couldn't get pics to show

Save them as an attachment, a recent change in forum software means these are automatically inserted into the text.

Pushing on an LED to get it to work implies a poor soldered joint. While moisture can make it worse it will take time. So I think that something is damaging the joints like excessive bending, maybe during fitting, but more likely is just poor manufacturing.

Humidity and pressure changes can also cause moisture to be generated inside the tube.

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While that would make sense as a failure mode - I cant see how that would be the case here.
All of my strips came straight off the reel, connections made and then attached to the soffit.
When mounted theres no movement as such.
Its just the fact that over a number of years I always seem to have an issue in the same area/length of strip.

4

Do you always buy the cheap strips, or use branded ones. The cheap chips are cheap for a reason.

5

Ok, Thanks for the Replys Mike - If I simply put it down to the chance that both sets of strips I bought are 'cheap' and hence were failing in a similar fashion - What 'branded' strips would you suggest are of good quality, or where should I be buying from?

I'm off work this week so hoping to get a chance to take down the strip and see what I can do.

6

Most of these strips come from the Far East so it is hard distinguishing between good quality and reject bin stuff. I would recommend that you buy from a major distributor, like Newark, DigiKey or Mouser. That I think gives you a better chance of getting good quality.

The fact that is the same area that fails might suggest that it is subject to more extreme temperatures and humidity. There might be say a reflection off a window that gives that section a double dose of sunlight, or something like that. Can you identify anything unique to the conditions that area is subject to?

7

Nope, nothing like that really.
The sun can't directly shine on it as it, as the strips sit appx 1cm higher than the front edge of the Fascia so they're really quite sheltered.
One of our cars parks near it, but even then I wouldn't say I've ever seen a 'reflection' off the car either, not to mention if it were to happen - the reflection would track along a fair section of the strip, and yet I only ever have problems within this area, of appx 0.5m from about 1.5m of start end.

As I said I'm hoping to take the strip down this week and have a look, not sure if I'll try remove strip from its silicone tube, or just cut the tube open and try carry out some surgery... :o

8

OK best of luck with that.