What was found
AFTER START OF NR 2 ENG, SMOKE COMING FROM AFT CABIN AREA. CREW SHUT DOWN RT ENG, APU, EVACUATED PAX & TURNED OFF ELECTRICAL PW. INVESTIGATION REVEALED NO SOURCE OF SMOKE. DETERMINED SMOKE COMING FROM AFT BAGGAGE AREA RT BULKHEAD AREA, AND A BLOWN CB GROUND RECIRC FAN, INDICATED A POSSIBLE VENTURI FAN MOTOR FAILURE. INSPECTION OF VENTRI FAN REVEALED A HIGH HEAT AREA. FAILED COMPONENT ELECTRICALLY ISOLATED, ACFT FLOWN TO HOME BASE. AN AD 94-11-03 HAD BEEN ACCOMPLISHED ON ACFT WHEN IT FIRST CAME INTO EFFECTIVITY IAW ALERT S/B 21-A150. REINSPECTED WITHIN PAST 24 MO AS PART OF AN MFG`S FLEXIBLE MX SCHEDULE PROGRAM 48 MOS ITEM. UNIT REPLACED WITH THERMALLY PROTECTED PART, REPLACEMENT PER S/B 21-142-3514A.