As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAV SMOKE EICAS INFLIGHT. STILL SOUNDING AT GATE. NO VISIBLE SMOKE OR FIRE. RESET SMOKE DETECTOR IN FWD LAV, CHECKED GARBAGE BIN HEAT INDICATOR, NO DEFECTS NOTED. OK FOR SERVICE. REFRENCE L/P 5675559 FOR THE REPEAT WRITE UP, PREV WRITEUP FWD LAV SMK DET ALERTED. THIS TIME WHEN GROUND POWER XFER TO APU BUS IT STARTED. REMOVED AND REPLACED SMOKE DETECTOR, AS PER AMM 26-14-01.