As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1201, JFK-FLL. RETURNED TO FIELD. EMERGENCY DECLARED. FUMES GRADUALLY GETTING STRONGER IN COCKPIT; PERFORMED BURNING SMELL OR FUMES COCKPIT INSPECTION REF AMM 24-00-00. FOUND SMELL TO BE COMING FROM THE BLOWER AVIONICS FAN THAT WAS OVERHEATING. R/R AVIONIC FAN REF AMM 21-26-57 OPS CHK GOOD, NO FUMES NOTED. A/C OK TO RETURN TO SVC. REF TSM 05-50-00-810-831A FOR ODOR IDENTIFICATION IN THIS CASE TYPE 9 COMING FROM AVIONIC BLOWER.