As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEPARTING DFW AND CLIMBING THROUGH 8,000FT AUTO PRESSURIAZATION FAILED & NO ASSOCIATED EICAS MESSAGE. FOLLOWED CHECKLIST AND MANUAL PRESSURIZATION WOULND NOT WORK AS WELL. INSTALLED SERVICABLE CHECK VALVE AT GROUND CONNECTION, PERFORMED PRESSURIZATION OPERATION CHECK IN AUTO AND MANUAL MODES OPERATION CHECKS GOOD IAW AMM 21-31-00.