As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT PACK WHEN SELECTED OFF DOES NOT PRODUCE A PACK OFF LIGHT ON OVERHEAD PANEL OR LEFT PACK OFF EICAS MESSAGE FOR 3 MINUTES. PERFORM OPS CHECK OF LEFT PACK IAW AMM 21-51-00, SYSTEM OPERATES NORMALLY , CAN NOT DUPLICATE FAULT. OPS CHECKED GOOD.