As it turns out, the local reseller doesn’t actually do Apple warranty work… so if I did get my computer serviced there, it’d cost $70 an hour, while I’m still under AppleCare. (I would have just gone to an Apple store if it weren’t two hours to the nearest one!)

So I called Apple instead, and they think the issue is indeed the power adapter (and that the replacement adapter I got yesterday, which turned out to be a third-party product, is a dud). So they’re shipping me a new official adapter and letting me ship back the old one.

Hopefully this one will work. And either way, I get a new adapter out of it.

More to come once I get the new adapter shipped…