As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 54 - MCI TO TUS - LAV SMOKE DETECTOR DID NOT TEST. MX PERSONNEL AT ONT PERFORMED TROUBLESHOOTING OF LAV SMOKE DETECTOR AND REMOVED AND REPLACED SMOKE DETECTION PANEL AND CONNECTOR. OPERATIONALLY CHECKED SATISFACTORY AND A/C WAS RELEASED TO RETURN FOR SERVICE.