As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BWI-BUF FLIGHT 3900. CREW REPORTED SMOKE COMING FROM RADAR GRAPHICS UNIT. SMOKE SUBSIDED WHEN UNIT WAS TURNED OFF. AIRCRAFT DIVERTED TO MDT FOR REPAIRS. NO EMERGENCY DECLARED. MAINTENANCE REPLACED RADAR GRAPHICS UNIT IN ACCORDANCE WITH DEHAVILLAND DASH 8 MAINTENANCE MANUAL. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.