Fine Drive 400 Software/Maps

Question

My FD400 will only show the map for the Fresno,CA area. It will not access the SD card with mapping software. It only shows a blue screen with an arrow for my area (PA). I receive all GPS info and can play mp3's but no maps. My SD card has to be corrupted or something wrong with internal program. Any help is appreciated. All functions work except trying to access mapping software on card. I do have the lantern in the lower left corner.