As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE LT BLEED AIR SYS FAILED IN FLIGHT. AFTER LANDING THE SYS WAS TROUBLESHOT & THE ENVIRONMENTAL CONTROL SYSTEM CONTROLLER PN 6636108500-3, SN 0330108 WAS FOUND TO BE DEFECTIVE. THE UNIT WAS R & R WITH A REPAIRED ECS. FUNCTIONAL & LEAK CHECKS OF THE BLEED AIR SYS WERE SATISFACTORY.