As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE FL370 LAV SMOKE WARNING APPEARED ON EICAS . SMOKE ALARM SOUNDED AFT LAV RIGHT SIDE. PASSENGER WAS IN LAV BUT SAID THE ALARM WENT OFF ON ITS OWN, NO SMOKE. PERFORMED OPERATIONAL TEST OF LAV SMOKE DETECT SYS PER BD500 A J26-16-00 TEST OK. NO HISTORY A/C OK FOR SVC.(LP# 6035372)