As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 578 FLL-HPN, AIR RETURN TO FLL DUE TO SMOKE AND FUMES IN CABIN, FUMES IN FLT DECK ON DEPARTURE. COCKPIT, CABIN SMOKE/FUMES QRH COMPLETED THRU BLEEDS OFF. SMOKE DISSIPATED MOSTLY AFTER RECIRC FAN TURNED OFF. PAX REPORTED A SQUEAL BEFORE SMOKE AND FUMES UNDER ROWS 8 AND SCREECH. (AIR CONDITIONING PACKS-SINGLE). REMOVED AND REPLACED NR 2 ACM IAW 21-51-05. OPS CHECK NORMAL.