I am in a kind of shock since yesterday night.
Was finalizing the beta of my build - getting the electronics to fit into a plastic box.
It was all working - I did not like those bullet motor cables - so I put some shrink tube on them to be save. Fitted the Focboxes inside and came to that idea that I could use those two Vedder Anti-Spark switches just in front of each box.
But it looks like one of those Anti-Spark Switches got its power-switch attached wrong - so it was ON instead of beeing off.
It was late - and it looks like I did connected all stuff from the battery side - as doing it normaly from the electronics and do attach the battery at last.
There was a little spark inside of the XT60 connector from the Anti-Spark to the Focbox.
But than only the red light of the 2.4gHz receiver started to light up. Not one of the Focboxes LEDs came up anymore.
Here you see the step of applying the shrink tube.
Measure if there is battery voltage on both side of the diode in question.
Measure if there is about 3,3V and 5V between any three legs on the GH12E(on backside of board)
Measure also all other same looking diodes if they got about 0,2V - 0,7V.