HEI Stock dist shut down

OK, so I've been doing great with a bone stock '73 318 electronic distributor wired to a GM HEI module on a heat sink using the correct coil for such an arrangement. Accidentally left ignition "on" for several days and now she's quit sparkin' altogether. For 10 points….what did I fry?
Got two set up this way so it's about time I learned to troubleshoot.