As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) FLIGHT CREW DECLARED A PAN PAN ON LOCAL ATC FREQUENCY RESULTING FROM A SCENT OF SMOKE OR ELECTRICAL SMELL IN THE FLIGHT DECK & AVIONICS BAY. ASSOCIATED WITH WHICH WAS LATER CONFIRMED TO BE EMANATING FROM A FAILED RECIRCULATION FAN. HAVE CONFIRMED AT NO TIME WAS THERE ANY VISIBLE SMOKE IN THE AIRCRAFT. LEFT RECIRCULATION FAN REPLACED IAW AMM 21-25-01.