So I had no issues flying this yesterday, however when I tried to this morning the displays wont turn on. If I try to just use ctrl E to start the engines the left engine starts but not the right, the warning light comes on and wont be turned off and the displays are still dark.
I dont have any of the FPS mods installed.
Same with me, this plane is now broken and it was my primary airframe while playing OnAir Company on the side. Very very disappointed with this patch; I’m off to play Crusader Kings 3 while Asobo sorts out this mess 
People in one of my Discord channels are reporting that if you reload the King Air in a different location, it can jump past this issue and be playable. I was able to with one restart in a different parking spot at the same airfield, others are reporting that you should send it to runway (so it starts with engines running, shut down, and then restart).
Still unacceptable that patching the game does this. Where is the QA?
I’ve been able to start off using the checklists, even autocompleting the checklists.
Yeah I’ve tried that. The battery turns on but I have no displays.
Battery on, no displays. Can’t start the right engine, only the left.
Asobo is the new Dovetail.
Same here. My King Air was working fine even post patch. But a few days later, I started experiencing the exact same issue you are.
I just flew KGEV -> TIST. During my climb all of the avionics died randomly. I had to toggle the switch to bring it back to life. I also had annoying issues where switches would become un-selectable, or other stuff in the cockpit interfered with selecting the switch. And lastly, the MFDs kept paging through menus occasionally without my input - pretty strange.
This isn’t an issue, but toggling de-ice on the cockpit window de-ices all windows instantly. The co-pilot window de-ice switch doesn’t do anything extra.
I’m having this problem right now. Ever since the patch, I’ve had the issue of the avionics turning off, AP turning off, and the panel lights dimming. It happened 5 times while on approach to KTEB yesterday. Now today, with no changed to the sim, I cant get the screens to come on at all.
I have seen something similar which seems to occur if the ATC window is open. Maybe it applies to all supplementary windows.
Discussed here. Make sure to keep upvoting this so it can be resolved.
I have exactly the same problem. Happend today for the first time. With both Beechcraft and Cessna 172 g1000. Turning on and off avionics for a few times helped. Then lights don’t respond (when wanting to dim the display eg) and then suddenly it works again… very very odd…
Also when this happens, the fd and ap don’t work at all…