How to turn on the PFD after it has shut off?

I was making a play-flight with the PA46T just for fun due to shortage of time and in doing so I forgot to turn on the Alternator.

Sometime during flight (10 minutes I guess) my PFD shut off as well as other instruments. I turned on the Alternator after that major omission and most of the other instruments (Garmins) came to life again BUT the PFD however remained BLACK.

I did not find a way to turn the PFD back on again without resetting the flight. Obviously documentation is lacking. So, how do I do it if that happens?