As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT APPROX FL 34O, FLIGHT ATTENDANTS REPORTED A STRONG SWEET ODOR IN CABIN & FEELING LIGHT HEADED, BEGAN TO NOTICE ODOR IN COCKPIT. DECIDED TO RETURN. RAN ENGINES 70 PERCENT N1 PRESSURIZED TO 4 PSI SWAPPED PACKS. REMOVED COFFEE MAKERS & OVENS, FOUND RESIDUE. CLEANED INSIDE & CALLED TOMC FOR CORRECTED ACTION. CHECKED WIRING AT G4 GALLEY COFFEE MAKERS. NO BURNED WIRES NOTED.