As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GATE RETURN. F/A REPORTED STRONG SMOKE/SULFER SMELL THROUGHOUT A/C. COCKPIT SMELLED A SULFER SMELL. GATE RETURN IN INTEREST OF SAFETY FOR INSPECTION. NOTE BAT PWR WHEEL CHAIR IN BELLY. ACCOMPLISHED AMM 05-51-58 CONDITIONAL INSPECTION NO SMOKE/ODOR FOUND. FLIGHT CREW QUESTIONNARE FORMS FILLED OUT.