Originally Posted by
suninmyeyes
It was an interesting lesson that what was clearly a massive short from the copilot's hand mic took out all the radios and not just the frequency that the copilot's transmit selector was set to. This would suggest some interrelationship between the bus bars of different radios.
And a frightening lesson as well, given the effort we (engineers) put into doing failure mode and effects analysis of aircraft systems. Having one of a redundant set of systems take out all function isn't supposed to happen. I'm guessing that the one bad mic dragged the entire audio control system down with it instead of triggering some sort of isolation/protection on that input (a breaker of sorts).
This also brings up the subject of an old thread: Adapting headsets with one connector type to another system. While I'm not going to step in and tell people not to do it, this is one possible consequence of an unapproved mod.