What was found
AIR TURNBACK, DECLARED EMERGENCY. SMOKE AND FUMES NOTICED IN CABIN AFTER TAKEOFF. REMOVED AND REPLACED LT AIR CYC MACHINE, RECIRC FAN (P/N 64505-1), COALESCER BAGS, AND HEPA FILTER PER MM. PERFORMED 5 MIN ENG POWER RUN AND PRESSURIZED ACFT, ALL SYS OPS CHECK GOOD PER MM.