I have owned a Go 5200 Wi-Fi for several years and it has been brilliant. However, recently it started becoming unreliable. This takes several forms: it just suddenly randomly goes black then, after a few moments, restarts itself. Sometimes using the menus they go jerky to scroll and are slow to react to taps. Other times, whilst navigating, the map freezes for a while and then very slowly catches up to itself. These problems began after updating the OS and maps at some point. I feel the machine needs completely erasing and reinstalling but I cannot find how to do that. I have tried resetting it but that does not help.