On some cold winter mornings, my dashboard stays dark. Later, sometimes hours later, it lights up normally. Any suggestions?
Assuming the dimmer knob isn't turned down accidentally, maybe you're hitting Luscious Garage | Blog | LG TV - Prius Dead Dashboard ? If so, see Combination Meter Warranty Enhancement | PriusChat.
You either have a temperature sensitive component, or connection problem. If you cannot get at the circuit board and perform heat and chill testing, a meter swap is the preferred method of fixing this problem. While I am quite comfortable doing board level maintenance, you have to first access it in order to fix it!
I'd print out the warranty extension at Combination Meter Warranty Enhancement | PriusChat, if you haven't received yours, so that can't play dumb.