What was found
GROUND BLOWER ON RIGHT PACK FAILED AFTER STARTING BOTH ENGINES. ELECTRICAL SMOKE AND ODOR IMMEDIATELY BEGAN FILLING COCKPIT AND CABIN. SHUTDOWN ENGINES AND PASSENGERS WERE PROMPTLY DEPLANED. CHECKED PACK FAN ROTORS AND WIRING, OPERATED BOTH PACKS WITH APU AIR AND ENGINE BLEEDS. ALL SYSTEMS CHECKED NORMAL, DISCREPANCY COULD NOT BE DUPLICATED AND AIRCRAFT RETURNED TO SERVICE.