What if the power goes out during an update?

While the progress bar is moving, the arriving firmware is only being downloaded and checked; the firmware you are running is untouched. A power cut then means the ticker starts up on its old firmware, the half-downloaded file is discarded, and the update is tried again at the next hourly check. Nothing you set is affected.

The delicate moment is short: after Almost done! and the line naming the new version, the screen goes dark for about seven seconds while the checked image is written into place. A cut in those seconds can leave the image partly written. The ticker then reports Update was interrupted on its start screen and tells the server, and it takes the next published version on its own if it can. If it cannot, contact Lee: Contact. That is why the screen says Keep me powered on!