What was found
AIR TURNBACK, AFTER TAKEOFF RECEIVED ECAM MESSAGE TO LAND AS SOON AS POSSIBLE, PULLED UP LAST LEG REPORT THAT INDICATED AVIONIC SMOKE FAULT. RESET CIRCUIT BREAKERS PER MX & CAPTS EMERGENCY AUTHORITY. BROUGHT UP AVIONIC SMOKE CHECKLIST & DECLARED AN EMERGENCY, TURNED BACK TO FLL AND LANDED WITHOUT INCIDENT. MX PERFORMED TROUBLESHOOTING OF AVIONICS CODING & SMOKE DETECTOR SYS. REMOVED & REPLACED SMOKE DETECTOR SENSOR AND SMOKE WARNING RELAY. OPS CHECK WAS GOOD PER AMM TASK 26-15-00-710-001. PART NAME; RELAY, MFG; ALLIED SIGNAL, P/N; E0245-28AO. VENDOR CONFIRMED FAILURE OF SMOKE DETECTOR S/N 1055. NO REASON GIVEN FOR FAILURE. PART DEEMED AS BEYOND ECONOMICAL REPAIR & WAS EXCHANGED WITH UPGRADED M&E.