Similar issue. Just purchased GTN750, opened up XP11.36r2 I believe. Opened up my new Carenado Premier 1a. GTN worked beautifully. Opened up Carenado PC12, GTN wouldn't power up. Opened up a few other aircraft, same thing, no power. Went back to the Premier, now it won't power on.
Help, my 10 minutes with this ad-don working was phenomenal;)