What was found
(SUP) - PILOTS REPORTED THAT THE PACKS SMOKED THE AIRCRAFT ON THE GROUND. MAINTENANCE INSPECTED AND CHECKED THE PACKS FOR LEAKS, NO LEAKS FOUND. OPERATED PACKS IN HIGH, LOW, HOT, COLD IN AUTO AND MANUAL FOR SEVERAL MINUTES. OPERATIONAL CHECKS WERE GOOD. MAINTENANCE ALSO INSPECTED THE GROUND COOLING FANS, ACM AND TEMP CONTROL VALVE PER MM 21-00-00.