My Sonos asked for a software update. I started the process, which failed, the restart never did. The network lights were blinking abnormally fast, no way there is that much traffic on the network. I searched the Sonos website that as one step of troubleshooting asked to reboot the router. I did, and at the point where network connections came back, the Sonos power supply gave out a loud short circuit sound and strong smell of ripe electronics.
The lightning into the power outlet killed my file server, too(!).

The data is safe, but the controller died. To retrieve the data, I opened my desktop computer to get spare Sata and power connections. It has been a while when that box has been open, so it was dusty. I vacuumed it, and now the fan is obnoxiously loud.
I should stop typing while the keyboard still works...
The router is fine, but I haven't yet tried the port where Sonos was connected. Still, surprisingly much hardware damage for a simple(?) software update!
(Btw, Sonos agreed to replace the device, and Buffalo agreed that a power glitch should not kill a server, even if it was in the same power outlet as a failed power supply. Not done yet, but they will take care of me. I'm not writing to Asus about the fan, though.)