As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ERI-PIT - FLIGHT 3978 UPON APPROACH INTO PIT THE CREW OBSERVED SMOKE COMING FROM THE CAPTAINS AUDIO PANEL. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND SWAPPED AUDIO PANEL FROM OBSERVERS POSTION INTO CAPTAINS POSITION AND ISSUED MEL FOR OBS. CAPTAINS OPERATIONALLY CHECKED GOOD IAW PROCEDURES. AIRCRAFT WAS RETURNED TO SERVICE. SUBSEQUENTLY THE OBSERVERS PANEL WAS REMOVED AND REPLACED WITH A SERVICEABLE UNIT.