LED not drawing current

I have 50 (out of a planned total of 80) 60-led strings of Adafruit Neopixels wired together, each one individually powered and grounded. Everything lights up fine until I get to string #48, which suddenly stops, the first pixel flickering weakly green. it appears to be drawing no current. my power supply’s input is 5V-60A, with three lines going out into six different bus blocks (three for power, three for ground), with about 25 strings attached to each bus block

I am certain that the string in question works (I’ve tested it). I also switched out the string leading into it and confirmed that one for working as well. I am certain that all my connections are solid and that my code is fine. Is there some really stupid obvious reason for this? Do I just need a beefier power supply?

Tell us what the power supply ratings are, show us schematic and show us a image of the wiring.

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48 strings * 60 LEDs * 60mA/LED = 172A.

60A supply sound a little underpowered.

CrossRoads, that's what I thought because I can't imagine what else it could be, but it seems a little odd that it would poop out right on the first pixel of the 49th string--or is that what you would expect to see for a weak power supply?

Put a volt meter on the string, see what you're getting. Switching power supplies can shut themselves down when they see an overcurrent condition.

Looks like the voltage is not actually dropping an excessive amount. Power supply doesn't seem to be overheating either. If I set the code to only start lighting strings up about halfway through, the problem persists. Seems like a dataline/software problem at this point but I can't imagine what it would be, my test code is so simple.

What Arduino are you using?

Everything lights up fine until I get to string #48,

So at 60 LEDs per strip and three bytes per LED you need 48 * 60 * 3 = 8640 bytes of memory. So a Mega and Uno are running out of memory at this point.