What was found
CREW DECLARED AN EMERGENCY DUE TO SMOKE IN CABIN AND SMOKE STOPPED WHEN "CABIN IFE" WAS TURNED OFF. EXECUTED SMOKE CABIN SMOKE QRH TO IDENTIFY IFE, THEN EXECUTED SMOKE/FUME REMOVAL QRH TO DISIPATE SMOKE. SUSPECT SMOKE WAS FROM IFE BECAUSE IT STOPPED WHEN REMOVED POWER FROM IFE IAW QRH PROCEDURE. ACCOMPLISHED FIM TASK 21-20-00-810-801-A NO ABNORMALITIES NOTED. ACCOMPLISHED ELECTRICAL ODOR INTEGRITY CHECK IAW MM 44-20-10, PAGES 5034-5036 VISUAL AND SENSORY INSPECTION SHOW NO EVIDENCE LTV SYSTEM IS COMPROMISED. ALL OPS NORMAL. FOUND DEBRIS ON HEAT EXCHANGER. RT AIR CYCLE MACHINE AND DUAL HEAT EXCHANGER WAS R & R IAW AMM 21-51-04 AND 21-51-05. OPS AND LEAK CHECKED GOOD.