As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL320, ACFT EXPERIENCE SMOKE IN THE CABIN. ACFT RETURNED TO DEPARTURE. INITIAL INVESTIGATION REVEALED TO A FAULTED COOLING TURBINE UNIT. FURTHER THE CONDENSER DRAIN LINE FROM THE TURBINE UNIT IS CRACKED FROM A PREVIOUS REPAIR MADE.