Garmin Black Screen on all G1000-Aircraft

[MichaMMA]

magneto switch is on both ?

EDIT: ah, and here an example topic about

Instruments screens are black

If you have Honeycomb Bravo and start the engine on with the “key”, you must turn it back to “both” position after the start. If you don’t, the starter is on and empties your battery. It happened to me too “facepalm”