I've been given a Nulink 2320 that is not working. On starting up, it says "loading Maps" then I select United Kingdom, press Next and after about 10 secs it shuts down and starts again. I have tried a factory reset, holding down the power button for 10 secs. It says "Erase all user data" - selecting yes or no takes me back to the loop. It is fully charged. Any ideas please?