As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: MAINTENANCE REPORTS LOUD POP DURING CLIMB-OUT 6 - 7 K / SHORTLY AFTER VENT BLOWER ECAM DIRECTING BLOWER OVRD / CABIN WOULD NOT PRESSURIZE / EMERGENCY DESENT INITIATED. EMERGENCY DECLARED. MAINTENANCE REPORTS AVIONICS VENTILATION DUCT WAS REPLACED. ALSO AVIONICS VENTILATION AIR INLET CHECK VALVE IAW AMM 21-26-42 AND 21-26-52.