Pioneer XDJ-XZ not recognising USB

The device started with error message E-8307, but after that it stopped recognizing it. I tried using different flash drives but without any change. All flash drives were formatted in fat32. It seems to be some firmware defect but there is no way to update the firmware because it does not recognize the flash drive. Everything else on the device works normally, including the 5V on the USB port. What can be done from this? Is there a way to update the firmware using another method or something else to be done?