As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EICAS RT PACK OFF. RAN C-L.PACK RETURNED TO NORMAL OPS. PROBLEM REOCURRED. ACCOMPLISHED TROUBLESHOOTING. NO FAULTS ON PACK TEMP CONTROLLER. PACK INOP ON GROUND. SUSPECT FLOW CONTROL VALVE PCN 643-9118. FLOW CONTROL VALVE LOCKED. REPLACED RT FLOW CONTROL VALVE, TESTED OK.