As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ATB, SECOND ATTEMPT, ON CLIMB OUT AVIONICS SMOKE ECAM. COMPLIED WITH PROCEDURE SNIFFER FAN. NO SMOKE OR FUMES DETECTED. AIR TURN BACK. AFTER BLOCK IN AND SHUTDOWN LIGHT REMAINS ON. FOUND SMOKE DETECTOR 13WA INOPERATIVE. REMOVED AND REPLACED 13WA SMOKE DETECTOR IAW MM 26-15-12. INSPECTED WIRING IAW WRM 26-15-00. NO DEFECTS NOTED.