As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EWR - CREW REPORTED THAT THE NR 1 PACK WAS BLOWING ONLY WARM AIR IN AUTO & MANUAL MODES WITH MINIMAL AIRFLOW, AND A BURNING SMELL AT LOW POWER SETTINGS. THE AIRCRAFT WAS RELEASED ON MEL 21-51-00-1 CONTROL NR 048227. FLIGHT 3138 IAH MAINTENANCE REMOVED AND REPLACED THE NR 1 PACK DUAL VALVE, OPERATIONALLY CHECKED WITH NO DEFECTS. REMOVED THE MEL, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.