This year I have 5v 2812B 4000px matrix. The dimensions are 80 vertical lines of 50px. I have sectioned them off as shown into lots of 18 + 18 + 24 + 20. Each section has its own power supply. They are being run by Pixlite using 14 ports. Each port can do 2 universes, in this case each port will be running 300px. I have drawn the image below to give a sample of the wiring, it doesnt show all the wiring as the picture would be a mess. I have injected power after every 2nd strip also backfeeding. The power supplies are grounded 1-2, 2-3, 3-4. The pixlite is being powered from Power Supply 1. I have wired together groups of 2 +ve's and 2 -ve's and wired them to fusebox and -ve of power supply directly. There are now 2 sections which I have still left to fix as unfortunately it looks like I have some dodgy strips, 3 replacement rolls are being sent. Can anyone see a problem with the grounding or anything else?