As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A/C WILL NOT PRESSURIZE IN AUTO OR MANUAL MODE. MAINTENANCE FOUND GROUND AIR CONDITIONING FLAPPER VALVE BROKEN. R&R'D GROUND CONNECT VALVE IAW AMM 21-22-04 , OPS CHECK GOOD. OPS CHECKED PRESSURIZATION IAW AMM 21-31-00. OPS CHECK GOOD. A/C OK FOR SERVICE