Originally Posted by rwayne
It is connected to a GMA 350c audio panel (stereo). It is the same on copilot transmit, carrier only. (Hadn't even thought of checking that!)
Thank you for the help.
Given that the GTR 200 has already been replaced, and the problem still exists, it would seem best to focus on why the pilot/copilot mic audio is not reaching the GTR 200 from the audio panel.
You don't say if the pilot and copilot are able to talk to each other over the audio panel intercom, but if so, this would tell us that the mic audio is getting to the audio panel from the pilot/copilot headsets.
I would remove the audio panel from the rack and inspect the pins on both sides responsible for transmitting mic audio to the GTR 200.
You might even find that just re-seating the audio panel in its rack will fix the issue.
You should also verify that no one has enabled the internal intercom on the GTR 200.