As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, FLIGHT ATTENDANT REPORTED THE LEFT AFT LAV SMOKE ALARM SOUNDING AND BURNING SMELL IN CABIN. SMELL CLEARED BUT LAV ALARM CONTINUED UNTIL RESET. FLIGHT CONTINUED TO DESTINATION. MAINTENANCE REPLACED THE APU. OPERATIONAL CHECK OK.