As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERTED DURING CLIMBOUT PASSING THROUGH 12000 FT, F/A HEARD AFT LAVATORY SMOKE DETECTOR CHIRP AND SMELLED ELECTRICAL SMOKE. COULD NOT DETERMINE SOURCE AND NO OTHER INDICATIONS. INSPECTED ALL WIRING AND SWITCHES, NTF. ALL LIGHTS GOOD. CYCLED DIMMER SWITCHES SEVERAL TIMES, NTF. INSPECTED APU INLET FOUND CLEAN. SMOKE DETECTORS OPS CHECK GOOD. PERFORMED DUCT BURNOUT IAW FIM 21-22. NO ODOR NOTICED.