Wireless is working again, yay!

So at some point during my trip to Saarbrücken for the qepHom last November, I managed to disabled the WiFi on my laptop. It has a hardware switch with an LED, and it somehow got into a state where it was permanently off, and clicking the switch didn't switch it back on.

I couldn't enable WiFi from Network Manager because it said it was disabled by hardware switch ... but I had no idea how to get it working again. I was even considering reinstalling on the off-chance that that might fix it.

But this evening I googled for "compaq nc6220 hardware wifi switch" and found this entry which linked to this one, which had the magic incantation!

tl;dr: after installing "rfkill" and running rfkill unblock wifi, the LED started flashing, I got asked for my keychain password, and I was connected to my home WiFi network! Yay!