As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DESCENDING OUT OF CRUISE ALTITUDE, AN ELECTRICAL BURNING ODOR CAME THROUGH VENTS. DECLARED AN EMERGENCY AND MADE AN UNEVENTFUL LANDING IN PIT. PACKS TURNED OFF BELOW 10,000 FEET AND ODOR SUBSIDED. MAINTENANCE REPLACED A BROKEN DUCT SUPPORT AND SECURED LOOSE DUCT. AIRCRAFT RETURNED TO SERVICE.