WS2812b strip stopped working,what could be the possible cause?

Hi, I'm using a 1m ws2812b (30 led/m) strip for my ambilight setup with adrilight, using an arduino mega. I cut the 1m strip into 5 smaller strips  ['data direction as per this description':  (5+5 leds in bottom) -> 5 leds at the left side -> 10 leds at the top -> 5 leds at the right side) ] and soldered them together, rechecked everything and installed it on my monitor. I'm powering it with a 5v 2a power supply and everything was working good for 3 days. Suddenly, the strip stopped responding to any data input from the arduino. Only the 6th led of the 2nd strip at the bottom lights up with 'green' colour as soon as I turn on the power adapter. 
I tried using Adafruit neopixel rgb strand test as well as fastled library's sample codes but none work any longer(they were working perfectly prior to this sudden failure). It's as if the strip doesn't care that the arduino is connected. The single led (6th one as per data line & 1st one as per divided section, on the 2nd strip) works when connected to the power adapter and lights on/off as per the power adapter's state. None of the other leds work or even light up. What could be the possible problems of the sudden strip failure? Any help would be highly appreciated.

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steveastrouk5 months ago

I've found that the inputs to these strips are very static sensitive. Have you tried the individual strips, and see if you can at least isolate the dead piece ?

Sudoer-_-me (author)  steveastrouk5 months ago

Update: I isolated the soldered strings and prima facie, it seems that the first led on the strip is damaged. I'll isolate that & reconnect to see if the 29 leds are all still working. Thanks for your inputs.

tmp_14510-Z45 Dazzle_20170517_1803441588187926.jpg

It may be worth putting a series resistor to the data pin on the first device next time, 1K or higher, and maybe a couple of decent clamping diodes to +ve and gnd.

Sudoer-_-me (author)  steveastrouk4 months ago

Thankfully, it was just the 1st led on the strip that burned out. I've replaced the previously placed 220ohm resistor with a 1K resistor and everything works well so far. Thanks for your replies.

+1

This is fantasy.. Obviously you will need more strip, unless static only killed the first ones in line.

Your a doubleE what do you do for static assembly ?

Use wrist bands and No feather brush cleaning recommended..

2+
Nothing is more deadly to sensitive electronics than static electricity.
All the "smart" LED's I had so far came with very destinct warnings about that on the packing.
And AFAIK once these LEDs got a shot too much they are useless.
As Iceng pointed out you need to be grounded with your equippment while working on them and same story for the mounting - once done you also have to make sure static won't be a problem in the future.
Meaning: No loose wires or contacts, properly grounded power supply and Arduino and so on.
Only if totally isolated static won't be an issue anymore - if in doubt put it all in a case or enclosure ;)

Sudoer-_-me (author) 5 months ago

Hey guys, thanks or your inputs. But, I'd like to point out that I took all necessary precautions to keep static from building up by being grounded to a cpu cabinet all the while as it's not easy soldering with an anti-static wristband. I used the anti-static band while mounting the strip to the monitor and isolated all wirings with electrical insulation tapes after mounting. I also used a c2200uF between the power rails(to compensate for frequent fluctuations in power draw while on load) and a r220ohm between the arduino's data pin & led strip:s data pin to cancel out static noises(if any). The arduino is grounded with the power supply's ground too.

What's weird is that only the 6th led on the strip works occasionally and the rest look dead to me. I'm waiting on a new strip to mount as ambilights and then I'll start isolating the individual leds on the strip to see if I can salvage any working ones. I expected there could be other reasons than what I had taken precautions for which is why I asked a question here. Thanks for your inputs though.