The LEDs adorning the 0D3 rectifier tube became unreliable:

After failing to plug in a different USB power supply, a close look at the USB connector showed the problem:

A bit of needle-nose tweezering extracted the culprit from the power supply’s connector:

I tried applying the world’s smallest dot of epoxy to the fracture, probably slobbered epoxy along the pins while reinserting it, and the Nano still doesn’t light up.
Given that knockoff Nano boards cost a touch over two bucks delivered, it’s not clear transplanting a connector from one of the never-sufficiently-to-be-damned counterfeit FTDI USB adapters makes any sense.