What was found
SMOKE IN COCKPIT DURING FLIGHT. OVERHEATED TRANSISTORIZED DIMMING ASSY LIKELY CAUSED BY ADDED ELECTRICAL LOAD DUE TO RECENTLY ADDED RADIO EQUIPMENT. SUBMITTER STATED AN EVALUATION NEEDED OF CURRENT DRAW ON SUBJECT SYSTEM. THAT DETERMINATION HAS NOT YET BEEN MADE ON THIS AIRCRAFT. THIS AIRCRAFT DELIVERED NEW IN 1984 WITHOUT RADIO. THE AVIONICS AND RADIO GEAR HAVE BEEN ADDED TO OVER THE YEARS WITHOUT BENEFIT OF ENGINEERING REQUIREMENTS OF SUBJECT CIRCUIT.