My Rand McNally GPS is about half dead. It must be getting power because it sends out coordinates but they're always the same....even after being powered off for days.

The coordinates are a location I drove by over a week ago. This happened a couple days before that too...and then worked ok for awhile. I think it might have been happening periodically for a longer time but I didn't recognize the symptoms then....just assumed I lost the signal.

Does anybody have any ideas on how to fix it?