I was sitting on the runway, preparing to take off in an A380 when all the displays when black. Like if one turned off the battery and/or Avionics switch. I tried turning off the battery and Avionics switch, neither had any effect on the aircraft, its as if those switches didn't exist! When flying the DH-106 Comet this does not occur. This also happened when getting ready to take off in a Piper Super Cub 180. I have not done anything with either of these aircraft, in terms of tinkering.
Would anyone have any idea what might be going on?