As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANT REPORTS ELECTRICAL BURNING SMELL IN AFT LEFT LAVATORY.MAINTENANCE ISOLATED THE SOURCE OF THE ODOR TO THE LEFT HAND AFT LAVATORY SINK DRAIN VALVE AND REPLACED IT PER AMM 38-32-41. A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED.