Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
Lets start with this reset. https://www.youtube.com/watch?v=xM6L14_A3gI
And then, update the internal software by connecting the device to your computer and then downloading and installing the garmin express software.
Once it has updated the device.. Attempt to use it again.. If it still misbehaves, then reply and let me know from what company you purchased the refurbished unit from. Thank you.
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.