As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT DECK AIR NOISY. COMPLIED WITH CHECK OF ORIFICE PLATES ALL PRESENT. WHILE RUNNING PACKS NOTICED AIRFLOW VERY LOW ON F/O SIDE. CAPTAIN`S AIRFLOW HIGH. FOUND ORIFICE CLOGGED AT CROSSOVER DUCT. CLEARED DEBRIS, ASSEMBLED, & CHECKED OK.