As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK, FLIGHT CREW REPORTED AVIONICS SMOKE INDICATION ON DEPARTURE. AIRCRAFT RETURNED TO CUN AND LANDED WITHOUT INCIDENT. PERFORMED OPERATIONAL CHECK OF EXTRACTION AND BLOWER FAN BY MCDU PER MM 21-26-00-710-001. NO FAULTS DETECTED.