What was found
AFTER ENG START CHECK LIST COMPLETED THERE WAS A STRONG ELECTRICAL SMOKE ODOR, FOLLOWED BY SMOKE COMING FROM BEHIND THE F/E PANEL (LEFT SIDE). AFTER PUTTING LINE AND TRANSFER SWITCH'S TO OFF, SMOKE STOPPED. BY PUTTING LINE AND TANSFER SWITCHES BACK TO NORMAL SMOKE NEVER STARTED AGAIN. MX PERFORMED A VISUAL INSPECTION OF AIRCRAFT ELECTRICAL COMPONENTS. NO DEFECTS NOTED, REMOVED F/E PANEL (51VU) FOR FURTHER INSPECTION. FOUND WIRE INSULATION CHAFED ON TRANSFER SWITCH NR 1. REPAIRED INSULATION ON WIRE AND REPOSITIONED IAW ESPM 20-53-29 VISUAL INSPECTION IAW ESPM 20-52-11 PERFORMED, AIRCRAFT ELECTRICAL SYSTEM TEST AND FUNTIONAL CHECK IAW 24-00-06, OP'S CHECKED SATISFACTORY. AIRCRAFT RETURNED TO SERVICE.