As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAVATORY SMOKE EICAS MSG ON DESCENT. NO VISIBLE SMOKE OR FIRE DEBRIEFED INBOUND CREW LAV CHIME CAME FROM AFT LEFT LAV(K) NO SMOKE OR ODOR NOTED FOUND LAV K TESTING NORMALLY. FOUND LAV M NOT TESTING REMOVED AND REPLACED LAV M TESTED IAW 26-14-00-735-001. OK TO CONTI UE