As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CLIMB SMOKE APPEARED IN THE CABIN. FLIGHT RETURNED TO STL. CHANGED THE RT RECIRCULATION FAN, P/N 606772-3, AND BOTH RECIRC FILTERS, P/N P196555. ALSO ACCOMPLISHED CHECKS OF FAN CONNECTORS AND WIRING. PERFORMED TEST FLIGHT TO CONFIRM CORRECTIONS.