What was found
AT CRUISE ALTITUDE FL310, AN ELECTRICAL SMOKE SMELL WAS DETECTED IN THE COCKPIT. NO VISIBLE SMOKE WAS NOTICED AND BOTH LEFT AND RIGHT 'RECIRCULATION FAN INOPERATIVE" LIGHTS ILLUMINATED. FLIGHT ATTENDANTS REPORTED NO SMOKE OR SMELL IN THE CABIN, BUT MID OVENS TRIPPED OFF. NO CIRCUIT BREAKERS OPENED. MAINTENANCE FOUND SHORTED WIRE BETWEEN PIN 6 AND 7 ON D864 PLUG OF THE APU/CARGO CONTROL PANEL. THE APU/CARGO FIRE CONTROL PANEL WAS REPLACED AND THE SYSTEM OPERATION IS NOW NORMAL. ETOPS CATEGORY 'B': DIVERSION OR TURNBACK