LED color drop off

Working on a new LED project but we are getting some weird amber color that feels like power drop off on the 5th LED tower of our setup.

Here are the specs:
7 LED towers each with 4 pixel strips of 71 LEDs in parallel. So we have 497 LED addresses but 4x that many lights.

Pixel Controller is Advatek A4s but we aren’t using power from it since it can only output 7A of power on an output

Power:
Estimating 50 mA per pixel each tower thats about 15 Amps per fixture and approximately 105 amps for the whole 7 fixtures.

We have two meanwell LRS-350-5 which are rated for 60A. The first 4 are wired to one and the next 3 are wired to the other. We have also tried the other configuration of first 3 on one and next 4 on the next. Still gets funky at the 5th light.

I have tried popping a buffer in between the 4th and 5th light (CD4050) but that actually causes more problems. Data gets all mangled prresumably due to ringing. My collaborator doesnt have any resistors and he is building the lights so i cant try to reduce that ringing and further the buffer aim. Also doesnt have an Oscope so can’t confirm that is actually what happens.

Here are some videos of the behavior. as you can see It only occurs when a majority of the lights are on. And on those last 3 lights. It handles color fine its just the white we have trouble with.

there was a behavior we saw before we went to debugging the wiring that had the 5th one as a nice bright white when only 5 6 and 7 were on and 1234 were off.

Color comes across fine. don’t have videos of it doing good color but just trust.

video 1 showing 4 bright white 3 amber

video 2 shows all 7 bright white but with less leds on

video 3 this shows the lights color flickering when we used a buffer.

Fixed this issue by using lower gauge wire. I think the impedance from the longer wire runs was just too high to get the 5V to the lights

Yeah 5V LEDs are very susceptible to voltage drop. I would highly recommend 12VDC stuff like WS2815 or similar if you can.

Those buffers might be slightly different timings than the chips in the LEDs since not all “WS28**” stuff speaks exactly the same timing in their protocols. Usually can’t mix different types / manufacturers…