As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COPILOT AUDIO CONTROL HAS AUDIBLE TONE WHEN ANY MIC SELECTOR IS PRESSED. SWAPPED PANEL WITH SECOND OBSERVERS PANEL. F/O PANEL, OPS NORMAL. SECOND OBSERVERS SEAT AUDIO PANEL WAS SWAPPED WITH FO AUDIO PANEL, AUDIO PANEL INOP. REPLACED ACP.