Have you tried a soft reset go tomtom.com, support, search reset, sel softreset, select your device, do as told.

You may want to backup all of you user settings prior to performing this reset.

To reset your device to factory settings, go to Main Menu > Change preferences > Reset factory settings.

If you do not have this menu option available, you will need to first select Show ALL menu options, located in the Change preferences menu.

Good luck dear.