For what it’s worth, I replaced the PCA9306 and the RTC (DS1307) and the RTC still does not work. Granted, my surface mount soldering skills are not very good, but I’m pretty sure I got them on there correctly. The good news is that the PCA9306 no longer gets hot. So what else could be wrong? I suppose it could be any number of things. If I get some time I’ll start poking around some more.