As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TYS FOR IAH - THE NR 2 PACK VALVE CLOSED MESSAGE WING A/1 FAIL. CREW DIVERTED TO MOB, WAS RELEASED IAW MEL 21-51-00/2 CAT (C) CONTROL/NUMBER 171254. LATER MAINTENANCE REMOVED AND REPLACED THE DUAL HEAT EXCHANGER AND OPS CHECK GOOD AND WAS REL.