What was found
UNABLE TO MAINTAIN CABIN PRESSURIZATION. FORWARD EQUIPMENT COOLING FORWARD EXHAUST VALVE DUCT WAS FOUND SMASHED AND THE FORWARD EQUIPMENT COOLING OVERBOARD EXHAUST VALVE HINGE WAS CRACKED. THE DUCT AND VALVE WERE REPLACED. A FOREIGN OBJECT PENETRATED THE DUCT AND DAMAGED THE VALVE. THE SHOP FINDING OF THE REMOVED VALVE INDICATED THAT THE ACTUATOR OPERATED NORMALLY BUT THE HINGE WAS CRACKED. THAT COULD CAUSE MISALIGNMENT OF THE ACTUATOR DOOR.