Dear Chrystal,
whether the PR1713 has a hardware error or something caused the device to lose its firmware. Both is odd but obviously not impossible.
If a coldstart (1) does not help here try to flash a firmware. It can be downloaded from HERE. You might need the tool FlashIt!. It can be downloaded from HERE. Then connect a serial interface to the built-in RS232 and press the Flash (2) button.
I attached the manual. Read the page EN-90 ff. carefully and follow the referenced chapters to flash the firmware.
If you can not cope with the instructions you can also send the device to the factory. Let us know!