As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALT WARNING HORN 35700 CABIN GOT TO 15500 O2 MASKS DEPLOYED PERFORMED DIGITAL CABIN PRESSURE CONTROLLER (DCPC) BITE PROCEDURE FOR BOTH NR 1 AND NR 2 CPC REF AMM 21-31-00-810-801. FOUND NO EXISTING FAULTS FOR BOTH CONTROLLERS AND NO FAULT HISTORY FOR THE NR 1 CONTROLLER. FOUND FAULT HISTORY FOR THE NR 2 CPC ON THE LAST FLIGHT LEG WITH THE FOLLOWING MESSAGES: SYS WIRING 001, OFV LRU FAIL 019, SEL PNL LRU FAIL 016. PERFORMED GROUND TEST AND SYSTEM STATUS TEST ON ON BOTH CONTROLLERS WITH NO FAULTS NOTED. REPLACED OUTFLOW VALVE. ALL TESTS OF CPC 1&2 PASSED.