As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LEVEL OFF AT FL 340, LEFT PACK LIGHT ILLUMINATED. PACK LIGHT DID NOT EXTINGUISH AFTER RESETTING MASTER CAUTION. PERFORMED QRH PROCEDURES, CABIN ALTITUDE STABLE ON RIGHT PACK. ACFT GROUNDED. REMOVED AND REPLACED LT RAM AIR INLET ACTUATOR IAW AMM 21-51-21. GROUND VERIFICATION OPS CHECKED GOOD. SYSTEM OPERATES NORMAL. NO FAULTS.