As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, FLIGHT CREW RECEIVED VENT EXTRACT FAULT. CREW ELECTED TO PERFORM AN AIR RETURN, SINCE VENT BLOWER WAS ALREADY ON DEFERRAL. ACFT LANDED UNEVENTFULLY. R & R BLOWER FAN 20 HQ IAW AMM 21-26-51. PERFORMED OPS CHECKED. OPS CHECK PASSED.