how do i get past Welcome screen after latest update?

[chemnrd]

Ellipsis won't do anything after downloading software update.  Stuck at Welcome screen.  Tried pressing power and volume down buttons.  Sometimes Welcome flashes away but then comes back.  Left it off charger all day and had dead battery.  Plugged in charger and we're right back to Welcome screen.  To be clear, i was having no problems at all before this update.