As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT PILOT NOTICED SMOKE IN THE COCKPIT COMING FROM THE MAP LIGHT DIMMING RHEOSTAT. MAINTENANCE INSPECTED AIRCRAFT AND DEFERRED THE MAP LIGHT ACCORDING TO COMPANY PROCEDURES. POTENTIOMETER PART NUMBER S2619-1 WAS NOTED AS DEFECTIVE COMPONENT.