As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN PRESSURE MANUAL CONTROL. BOTH REGULATORS FAULTED. OPERATED IN MANUAL CONTROL. FOUND BOX LIGHT ILLUMINATED WITH A CODE 70 WHILE TESTING BOX .REMOVED AND REPLACED PDPU 54GB AND TEST OK PER ABOVE REF. PRESSURE CONTROLLERS BOTH TEST OK REF TSM 21-30-00. AC OK FOR SERVICE.