It’s the exact same issue many of us are experiencing since the previous patch went online.
No Power since the beginning, you push the buttons, hear the clicks, but nothing happens.
That what I mean with well known. It’s been reported two weeks ago to Asobo and they replied they are on it. Unfortunately they did not fixed it yet.
There are at least 10 threads on the matter:
Setting GROUND AIRCRAFT DENSITY to 0 solved the issue for many of us. Then someone tried to SET GENERIC PLANES to ON, and also that helped.
It’s a matter of fact that it is a BUG that Asobo need to solve, what I am saying is that is a known issue and many of us where able to workaround it with the posted solutions.
I myself am not having that issue anymore. And I was the very frustrated first one who reported it after 5 minutes last patch went online.
That said, if you are saying it does not work, I am sorry to hear that, because it means that it could show up again.
EDIT:
when the game starts, all the planes on the ground are initiated, so some of them issue immediately power off commands, that’s why it can happen right a the beginning. But sometimes it happens after takeoff, when you are mid air, suddenly everything goes dark, and you are doomed. That was caused by the same reason: a plane on the ground issued a power off command, and it was captured by your plane. Event Dispatching issue, we developer call this. Your plane catch an event dispatched by a similar plane, another a320 on the ground. It seems Asobo did not filtered events correctly.
One of the threads:
https://forums.flightsimulator.com/t/1-8-3-0-a320-cold-dark-not-working-anymore/273564?u=rizal72
**EDIT2: **
VERY IMPORTANT! Always start first external power, then batteries!