Thanks for the info, Doc.

The strangest thing... today my wife came home and absent-mindedly
pushed the garage door remote control -- and it opened! I got home
shortly thereafter and tried it myself, and sure enough. There was a
faint smell of electrical smoke in the air. I'm sure the unit is on its
last legs, but does the fact that it's operating again still sound like
a capacitor problem?

-Fleemo