As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CRUISE FA'S REPORTED A STRONG SMELL IN THE VICINITY OF AFT LAVS THAT WAS BEST DESCRIBED BY THEM AS BURNING RUBBER. THE SMELL WAS BRIEF IN DURATION APPROX 1 MIN AND COMPLETELY DISAPPEARED WHILE THEY INVESTIGATED. THERE WAS NO ONE IN THE LAVS AT THE TIME. MAINTENANCE FOUND SOURCE OF THE ODOR VACUUM GENERATOR.