I recently posted about problems I was having with my Nav 5 being stuck on the calibration screen. One gentleman replied that he was able to resolve issues on his GPS with a new memory card. I tried it and it worked! I upgraded my memory card from a 64G to a 128G memory card. I then did a hard boot. I then had to calibrate it and go through the initial settings like it was a new unit. It now works like a new unit! Thanks for your suggestions. I figured it saved me around a $1000.