Well, my shift registers arrived yesterday. I was very excited to get them soldered in and to see The Resistorganizer 1.0 do the thing will all its blinkenlights. 

Alas, this is where trouble reared it's unconventionally pretty head.

Once installed, the LED don't light up at all now. My guess is that my schematic had some wiring wrong (I've since revised the schematic before I knew of this problem and didn't save the previous version.<face_palm_emoji>, but I can refer to my original files sent to the PCBA house)

So, I started cutting out shift registers to see if the lights would come back, at least to the first two registers which worked before. 

As you can see in the photo, I've clipped out two so far with no luck. So... keep clipping? Let's hold off for now. Time to get the multimeter out and see if I can tell what's what. Then, we'll get destructive again. 

Yea, yea, yea... I should go find the file with the board schematic and start troubleshooting there. That makes the most sense. But I'll spend 10 minutes finding the file and 45 minutes putzing around the kitchen because, for whatever reason, the mind really doesn't want to engage that way. So, we're working with the mind I've got.