What was found
WHILE ON GROUND AT ASE PRIOR TO BOARDING PASSENGERS, CREW NOTICED SMOKE COMING OUT FROM THE AFT CLOSET AREA, CREW DISCHARGED FIRE BOTTLE INTO AREA. TROUBLESHOT AND FOUND AIRSHOW SYSTEM INOPERATIVE AND AUDIO VIDEO AMP BREAKER POPPED, INSPECTED MONITORS AND FOUND FOIL FROM RIGHT AFT MONITOR PINS. INSPECTED AFT CLOSET AND FOUND THE PASSENGER ENTERTAINMENT AUDIO AMPLIFIER WAS THE SOURCE OF THE SMOKE AND ODOR. REPLACED AMPLIFIER. SYSTEM NOW OPERATIONAL BUT NO AUDIO OR VIDEO. DEACTIVATED PASSENGER ENTERTAINMENT SYSTEM AND SECURED AV AMP BREAKER.