I was on this flight just about 4 weeks ago. As we were pushed off the gate, the same thing happened: complete silence, all lights went off, i.e. a complete loss of power. Captain came on to say that auxiliary generator did not start properly, but they will restart it again in about five minutes and see how it goes. Everything was fine after that, but I wonder if it was the same bird with a recurring problem? May very well be just a coincidence, of course.