If your map has disappeared from the screen, is not visible, you cannot see map, or just it shows a blue screen with airports and airspace on it and no terrain or roads/rivers, please do the following:
Check that SD card is inserted in EFIS, shows the message 'SD CARD MOUNTED' when inserting it
Check that the SD card has the Navidata, Vmap and Terrain files found here on it: https://www.michiganavionics.com/database-updates/
Check that the map is in Vector mode: Press SHIFT > MAP [5] > Change Map Mode to Vector
If the map mode was in Raster mode, and you didn't switch it to Raster mode, this means that the CR2032 watch battery is flat. Please see this article: CR2032 Battery Flat
Check that the map is in Vector mode: Press SHIFT > MAP [5] > Change Map Mode to Vector
If the map mode was in Raster mode, and you didn't switch it to Raster mode, this means that the CR2032 watch battery is flat. Please see this article: CR2032 Battery Flat