Strange situation. Can’t get pixels to light up after soldered together

[Srmorgan]

I’ve got a strange situation I’m hoping someone has some insight on. I have a 100 count star that the last thirteen pixels went out on. I changed the last good and first bad pixel but they still are not working. So I hooked up the 13 non working pixels to a pixel tester and they worked fine. I hooked up a known working pixel to the good pixels and it worked. So I used alligator clips to hook up the good to the 13 previously nonworking but are actually working pixels and they all worked. So I soldered them together and I tested them and the last 13 are not working again. So I cut them apart and hooked them together with the alligator clips(just a 6” strip of pixel wire with three alligator clips at each end) and they now all light up. It’s a little frustrating to say the least. They are 5v pixels and power injected. What’s going on. I also did a continuity test on the v- and v+ and they tested good. They read at 4.9v at the end and I tested the signal strength between the good and bad and it read at 2.9v I didn’t test the voltage on the signal strength while using the alligator clips.

 

[Srmorgan]

I triple checked that the wires were connected correctly and in proper direction.

 

[Skymaster]

The data line will never show 5V as it's constantly flipping between 5 and 0V for the 1's and 0's across the line. So seeing 2.9V is pretty reasonable there.

Did you change the pixel just before the 13 that were out (pixel #86)? It's likely that's the bad one - it's not outputting data for the rest of the string.

 

[Srmorgan]

I did replace it. But if it was bad then it wouldn’t light up the last 13 when using the alligator clips. So it must be good.

 

[Skymaster]

Ahh, gotcha, sorry, there was alot going on and I misread what you had written.
With the alligator clips, and the pixels working, wiggle the wires where the enter the pixel body, on both pixels (86+87) - it's possible that one has a bad connection, and so the different angle of wire due to the inserted clips is causing it to be intermittent and work.

 

[Srmorgan]

I finally fixed it. I had to cut another pixel off of the first section. That star had two lights on it that were just staying on during setup and wouldn’t change colors while testing out sequences. So they both must have gone bad and been next to each other. I just don’t understand why it would Work while using the alligator clips. The last time I tried soldering them together before cutting another node off I finally got them to flicker but they came on in the wrong colors then stopped working. There’s a picture of them being clipped to the star with the alligator clips and working. I forgot to take a picture of when they were flickering after soldering them on.