As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED, EMER DECLARED, LANDING UNEVENTFUL & ACFT OVERWEIGHT. DURING CLIMB A BURNING ODOR WAS DETECTED IN CABIN & COCKPIT. QRH PROCEDURE PERFORMED. ODOR & FUMES WERE INTERMITTENT DURING APPROACH. PERFORMED ENG & APU RUNS WITH NO ODOR FINDINGS. INSPECTED CARGO & ELECTRONICS COMPARTMENTS WITH NO ODOR FINDINGS. FOUND FWD CARGO SMOKE DETECTOR FAN INOPERATIVE. R & R FAN. SYS CHECKED NORMAL.