As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEPARTED KLAX AND FOUND NR 1 PACK SYSTEM INOPERATIVE. NO PRESSURIZATION. RETURNED TO KLAX. NO FUEL WAS DUMPED. FOUND NR 1 PACK CONTROL VALVE CONNECTOR LOOSE. SECURED NR 1 PACK CONTROL VALVE CONNECTOR. OPERATIONAL CHECK GOOD IN ACCORDANCE WITH AMM 21-00-00.