The simplest way to test the cards might be to either set up an ad-hoc peer-to-peer connection between them, and se if they can talk to each other, or take them to the local internet cafe/Starbucks/whatever, and spring for a few minutes of connectivity to test them. Or just "borrow" a neighbor's connection for a few minutes ;)
Nothing was touched in the configuration since when everything worked well, and the only intervening "cataclysmic" event was that HD hiccup.
I have heard it is possible to make a small EMP with car parts, such as the starter. Common sense would seem to indicate such a pulse could be produced by any sudden change in spin angular momentum, such as a what might cause a 5400 RPM HD to suddenly stop spinning.
Starbucks should not be necessary since I just put in a brand new router.