After finding out how to test the PTC relay (QP2-4.7), I bought a replacement from AppliancePartsPros. Came within a day and I've got a cold fridge again.
Two months ago, the kegerator turned off and wouldn't start. Left it unplugged for a while, and it started up and ran until yesterday. Today it won't start, even after being unplugged all night. Plugging in triggers a "click" every 30s (irregular), but no motor start. It's a spring 2009 buildup...