Replaced an old ceiling fan/light combo with a new Hampton Bay unit. After attaching wiring and securing the fan motor to the support bar, I flipped the wall switch and tested the pull chains; both fan & light worked fine.

But after attaching the motor housing, fan blades and glass lamp shade, neither fan nor light will turn on. Circuit breaker is fine, and I don't think I did anything to compromise the wiring, but I can't figure out what the problem is. Are there any common ceiling-fan tricks or traps I don't know about?

Hokay, egg on my face. The wall switch, having gone unused for so long (as the fan it controlled had been dead for a while now) was just a little sticky, and would look "on" while still sticking to "off." A few vigorous clicks, and the switch, and fan/light work fine. Sorry or the false alarm.