Instead of a firmware file, you should ensure you are using the latest version of the management software to handle file transfers and device settings: Sound Organizer Ver. 2.0.03
Before attempting an update, verify the version currently installed on your recorder: Press the button on the side of your device. Navigate to Settings using the control dial. Select System Information . sony icd-px470 firmware
Before you search for that firmware file again, check your version, back up your recordings, and always download directly from Sony. This $80 recorder, when paired with the correct firmware, rivals devices three times its price. Instead of a firmware file, you should ensure