I remember being on a 787 not long after they were introduced and after boarding, we had a 20 minute delay because of an equipment problem that required "rebooting the plane" (the pilot's words). They did a full power shutoff, the cabin lights went off for a few minutes (and the cabin quickly warmed up because the A/C was off and the electronic window shades turned clear), then about 20 minutes later the pilot said everything was good and we were ready for departure. The rest of the flight was uneventful.