As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED NO AIR FLOW FROM ANY VENTS WHEN BLEEDS WERE TRANSFERRED TO ENGINE AFTER TAKEOFF. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED, R & R LT PACK VALVE AND PERFORMED CHECKS IAW AMM. ACFT RELEASED FOR SERVICE.