How I wired power to a wall of matrix panels without the headaches

I built a six panel wall last winter and went the soldered pigtail route instead of a terminal block. Stripped the ends of some 16 gauge garden variety hookup wire, tinned everything, and soldered a short lead directly to each panel connector, then heat shrunk the joints. Ugly but it has never given me a minute of trouble, and there are no screw terminals to back out over time like you mentioned.

For the branches I actually used leftover speaker wire from a home theater project and it has been fine, since each run is only a foot or so to its panel. The main feed from the supply is much heavier cable.

One thing I did that saved me headaches later was putting a small blade fuse holder on each branch. When a panel eventually failed on me, the fuse popped on that one line and the rest of the wall stayed up while I figured out which one it was.

The fuse holder idea is smart, I wish I'd done that on mine. I put one fuse only on the main feed, so when a mouse chewed thru a branch wire behind the frame the whole wall went dark and I had to pull every panel apart to find it. Next rebuild I'm fusing each branch like you did. Also second the tug test, had a ground work loose on mine once and it looked exactly like a data problem untill I wiggled the wires.

That terminal block approach worked for me too, but the real game changer was a cheap ferrule crimping kit. I was shoving stranded wire straight into screw terminals and a couple strands always folded back out, which is probly why my grounds were flaky for months. Crimped ferrules on every end and everythign cinched down clean. Also put a blob of hot glue over the data connector on each panel after a corner panel dropped out whenever the frame flexed.

Gotta push back on the speaker wire part. 'It's been fine' doesn't tell you much, because the question is wether that stuff is thick enough for what a panel acutally pulls at full white, not whether it survived a test pattern. A foot long run helps you, sure, but some of that thin theater cable is barely bigger than doorbell wire. Pull a strand out and compare it to what the panel's own power leads use, match that or go bigger, and you're set. Also worth checking the copper is actually copper, some of that leftover wire is copper clad aluminum and it creeps loose under screws.