As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#1780, FLL-DCA. (AIRCRAFT PERFORMED AN AIR TURN BACK TO FLL) 'LAV SMOKE MASTER WARN AT 10K UPON DEP CAME ON AT LEAST 3X DURING FLT, AIR RETURN FLL; FOUND #MAU 3 9/10 MODULE AT FAULT. REMOVED AND REPLACED IAW AMM GENERIC I/O MODULE IAW AMM 31-41-06. LOAD ANS TEST GOOD A/C OK FOR SERVICE.'