After powering up,the screen shows the sd card...

Question

I've had this gps for 2 years and never had a problem this it. after using the unit today to my destination, the unit operated fine. I powered the unit up to come back and the screen showed the picture of the unit with the sd card needing to be placed in the unit. The problem is the card was already in the unit. I took the card out and replaced it to see if the unit was operational, it was not. There was nothing done to the unit other then turn it off and turned it back on.