As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RTFL DUE TO NR 2 PACK FAILURE & NR 1 PACK'S CURRENT DEFERRAL. AFTER ATB, ON GROUND TESTING INDICATING NORMAL SINGLE PACK OPS-PERFORMED PACK TEMP CONTROL TEST- OK, REPLACED TURBINE BYPASS VALVE - ALL OPS TESTS ARE NORMAL- NO REPEATS SINCE ORIGINAL.