What was found
DURING ROUTINE FLIGHT, SMOKE EMITTED FROM UNDER INSTRUMENT PANEL, NO FIRE. AIRCRAFT MADE SAFE LANDING, NO DAMAGE. INVESTIGATION FOUND LANDING LIGHT FLASHER MODULE TO HAVE OVERHEATED. UNIT CONTINUED TO OPERATE NORMALLY, EXCEPT OVERHEATING. TESTS ON MODULE SHOWED 1 OF 4 TRANSISTORS, PN IRFZ40, HAD FAILED AND CIRCUIT BOARD OVERHEATED. MANUFACTURE RECORDS SHOW MODULE PRODUCED IN BATCH NR 1. PRODUCT IMPROVEMENT CHANGE SUBMITTED TO FAA FOR APPROVAL TO IMPROVE HEAT-SINK AND ADD THERMO FUSE TO POWER CIRCUIT TO PREVENT SMELL/SMOKE. SERVICE LETTER TO BE SENT TO ALL OWNER/OPERATORS. VNY MIDC ADVISED. STC SA5480NM.