As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED SMOKE IN THE COCKPIT, POSSIBLY FROM THE F/O'S READING LIGHT. THE AIRCRAFT RETURNED TO DEPARTURE WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND FOUND THE COCKPIT WIRING TO BE SATISFACTORY AND THAT THE NUMBER ONE ACM HAD SEIZED CAUSING THE SMOKE. MAINTENANCE REMOVED AND REPLACED THE AFFECTED ACM., OPERATIONALLY TESTED WITH NO DEFECTS NOTED AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.