What was found
CREW REPORTED, CABIN SMOKE ONCE AIRBORNE WITH ENGINE BLEED SELECTED ON. AIRCRAFT RETURNED TO NEWARK, LANDED UNEVENTFULLY. MAINTENANCE FOUND CABIN RECIRCULATING FAN INOPERATIVE. REMOVED AND REPLACED CABIN RECIRCULATING FAN IAW EMB145 MM 21-24-01, OPS CHECKED GOOD. ALSO, PERFORMED EMB145 FIM TASK 21-20-00-810-801-A, NO SMELL IS NOTICED IN CABIN, RAN ENGINES TO VERIFY SMELL, NO SMELL NOTED. AIRCRAFT RETURNED TO SERVICE.