As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED LAV SMOKE WARNING INDICATION AT 4000 FT ON CLIMB OUT. THE ACFT RETURNED TO DEPARTURE AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE FORWARD GALLERY SMOKE DETECTION PANEL AND THE DAU2. OPS CHECKS WERE GOOD. THE ACFT WAS TEST FLOWN SATISFACTORY.