First pixel in line dies every year

[jasondavid]

I've moved to a new house and have the opportunity to permanently install pixels on my roof line again, this time learning from my mistakes. One thing that plagued me every year with my old setup was that the first pixel in the string of 50 would die and cause the entire string and everything connected after it to stop working too. Through troubleshooting I found that cutting out that single node and splicing in a new node/pixel would bring the show back to life! In some cases, where I added a home made jumper between two factory strings, I would have to replace the pixel after the home made jumper as well. I've tried everything, from: 

-running the lights frequently during the other seasons... This seemed to preserve the pixels for some reason

-adding an F-amp: inconclusive results as I had a failure last year but moved before I could troubleshoot it

I'm just confused as to why this is happening only for the first pixel and only where I splice in a jumper line. When I connect two factory strings together directly this doesn't happen. Any ideas? 

[JonD]

I do not believe this a common problem.  At least I have not seen anyone else mention this and never had it myself.  If you can replace the pixel and it repairs, maybe check you power supply output voltage levels, possibly check to make sure there is no unneeded strain on the wires.   I have found that if the pixels can sway in the wind, or if gravity is pulling on things too hard, I will have a lot more repair issues during the season.  Make sure you zip them down well, they don't need to be super tight, just tight enough to minimize them from swaying back and forth in the wind.  Could your connectors be corroding such as using indoor instead of outdoor type? 

What gauge/type of wiring are you using?
What type of connectors are you using to connect them together?
What types of lights are you using?   5v or 12v?
Long are your lights strings and how many?

[breese]

I'm just confused as to why this is happening only for the first pixel and only where I splice in a jumper line. When I connect two factory strings together directly this doesn't happen. Any ideas? 

What are you using to splice the jumper with?

[jasondavid]

I do not believe this a common problem.  At least I have not seen anyone else mention this and never had it myself.  If you can replace the pixel and it repairs, maybe check you power supply output voltage levels, possibly check to make sure there is no unneeded strain on the wires.  I have found that if the pixels can sway in the wind, or if gravity is pulling on things too hard, I will have a lot more repair issues during the season.  Make sure you zip them down well, they don't need to be super tight, just tight enough to minimize them from swaying back and forth in the wind.  Could your connectors be corroding such as using indoor instead of outdoor type? 

What gauge/type of wiring are you using?
What type of connectors are you using to connect them together?
What types of lights are you using?  5v or 12v?
Long are your lights strings and how many?

Using 18 gauge wiring
Using butt splices with heat shrink marketed to waterproof connections 
12v lights
Power injected after about 150 bulbs. Total end to end strings are about 450 bulbs. Each string is 50 bulbs.

[jasondavid]

I'm just confused as to why this is happening only for the first pixel and only where I splice in a jumper line. When I connect two factory strings together directly this doesn't happen. Any ideas?

What are you using to splice the jumper with?

Waterproof butt splices 

[JonD]

Nothing sticks out in your response.  I have seen some lights needing slightly lower voltage such as 11.9 volts instead of 12 volts, and some vendors even confirm the output voltage before shipping power supplies, but odd it is only taking the single first bulb in the string.  Are you using Meanwell power supplies?  Maybe try a different connector next time?  Maybe others will have suggestions.
 

[steve123]

Do you turn the power to the string off but leave the controller powered?  Doing so can cause damaging current in the first pixel when the string is off but the controller pixel data buffer is driving the data line high.

[grant.simpson]

I install pixel strings on parade floats and this problem and in our case this problem is almost always because the wire going into the first pixel flexes a lot and if you look under a good magnifying glass in many cases you can see the broken solder joint.  We started securing the lead between the first pixel and the connector very well and the problems stopped.  It might not be what is going on with your situation but it sounds the same.