As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - DURING TAXI, LAVATORY SMOKE ALARM BEGAN TO CHIME WITH STRONG ELECTRICAL ODOR IN VICINITY OF LEFT AFT LAVATORY. NO BREAKERS TRIPPED AND ODOR DISAPPEARED. REPLACED 31 AB OVERHEAD BALLAST THAT WAS BAD. REPLACED AFT LEFT LAVATORY SMOKE DETECTOR. SYSTEM GROUND CHECK NORMAL OPERATION.