As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT PACK LIGHT ILLUMINATED ON T/O ROLL AT 100 KIAS. AFTER T/O, PERFORMED QRH CHECKLIST. PACK RESET OK. GROUNDED - YES. FOUND LT PLENUM FAN BYPASS CHECK VALVE AND HINGE PIN MISSING REF AMM 21-51-03. REMOVED AND REPLACED LT PLENUM DIFFUSER ASSEMBLY. REF AMM 21-51-03. OP CHECK GOOD. NO LEAKS FOUND.