What was found
SMELL OF SMOKE DETECTED ON FLIGHT DECK AND MAIN CARGO DECK WITH LEFT PACK ON. SHUT PACK OFF, SMELL CONTINUED. SMELL APPEARED OF ELECTRICAL ORIGIN. INSPECTED LOWER E&E COMPARTMENT, UPPER AND LOWER CARGO COMPARTMENTS WITH PACKS ON AND OFF. INSPECTED BOXES AND ASSOCIATED WIRING AND CIRCUIT BREAKER PANEL. INSPECTED LEFT AND RIGHT PACK COMPONENTS. NO DEFECTS NOTED. RAN PACK FOR 1/2 HOUR WITH NO SMELL NOTICED. COULD NOT DUPLICATE.