LED Wiring Issue? LEDs flicker and change when power cable is moved

I have an Arduino MKR1000 hooked up to an Addressable RGB LED Strip. The strip has 5 wires factory soldered onto the beginning of the strip.

(2) 5v
(2) Gnd
(1) Data

I have a 5v 8a power supply hooked up using a female DC power adapter which connects directly to (1) of the 5v wires and (1) of the Gnd wires. That power goes directly to the LED strip. The remaining 5v and Gnd wires that are connected at the same solder points as the other ones then go to the VIN and GND pins on the Arduino. Lastly, I have a wire coming from pin 7 on the Arduino, into a resistor, then into the Data wire on the LED strip.

Everything was working fine with this setup for a few weeks while I soldered the LEDs together and attached them to their final resting places on a piece of wood. Finally, I soldered all of these connections together and heat shrunk them.

Now, when I plug in the power adapter, I don't see any of the LEDs come on. I would suspect that when I soldered the wires together, something didn't come into perfect contact, but the Arduino still gets power, so I know the 5v and Gnd lines are connecting properly. This leaves me with the suspicious that the data wire is at fault.

HOWEVER, if I spin the male DC plug on the power cable while it's plugged into the female DC adapter, I see lights come on and behave erratically. They flash colors they're not supposed to be set to, and it seems random as to which lights come on and which stay off.

My question is: where should I be looking for the source of this problem?

I don't think it's a ground issue because the wiring worked fine before I soldered everything, and the Arduino gets power properly which from my understanding would only happen if both 5v and Gnd were both connected correctly. I don't understand how it could be a data line issue if jiggling/spinning the power cord in it's socket will cause lights to come on. If it is a data line issue, should I pull the resistor out and put a new one in the circuit? Could this one have been fried when I put the heat shrink tubing on?

Anyone have any ideas? This is my first electronics project so I'm a little out of my element, but I've made it this far so I was feeling really good about it. I'm willing to explore options or provide more information if needed. Thanks!

-Stephen

"Lastly, I have a wire coming from pin 7 on the Arduino, into a resistor, then into the Gnd wire on the LED strip."

Why

Not sure if your strip can work with the MKR1000.
Most addressable LEDs require a VCC*0.7 = 3.5volt HIGH data level when powered by 5volt.
Something a 3.3volt Arduino can't deliver.

That said, I have read that some have succesfully done that.
Leo..

Measure the power voltage directly on the LED strip terminals.
You should boost the signal using 74LS04 for example.

INTP:
"Lastly, I have a wire coming from pin 7 on the Arduino, into a resistor, then into the Gnd wire on the LED strip."

Why

Sorry, that was a typo. I have updated the original post. The wire goes from pin 7, into the resistor, then into the Data wire on the LED Strip.

jendalinda:
Measure the power voltage directly on the LED strip terminals.
You should boost the signal using 74LS04 for example.

Where do I place the multimeter leads to get the desired reading? What voltage should I be looking for?

Wawa:
Not sure if your strip can work with the MKR1000.
Most addressable LEDs require a VCC*0.7 = 3.5volt HIGH data level when powered by 5volt.
Something a 3.3volt Arduino can't deliver.

That said, I have read that some have succesfully done that.
Leo..

Interesting... The LED strip I'm using is https://www.amazon.com/dp/B01533H3CG/

If the strip required such a level on the Data line that is not compatible with my Arduino, why did it work without issue for weeks and suddenly stop working? Wouldn't it have never worked since the Arduino couldn't provide the data level the LEDs were looking for?