As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED OF FLIGHT WHEN FAIL IN RIGHT AIR CONDITIONING SYSTEM AND ADVERSE WEATHER CONDITIONS. AIRCRAFT FLIGHT WITH RT AIR CONDITIONING SYSTEM DEFERRED IAW MEL 21-1. DURING OVERNIGHT SERVICE, RT PRESSURE REGULATOR VALVE WAS REPLACED IAW MM 21-31-06, TEST CORRECT.