Make sure your new card is formatted correctly (Fat32). Use
SDF formatter if necessary.
With your new card either in a card reader, or (if in the scanner) by connecting the scanner to the pc, and pressing
E (Enter) at the prompt to choose 'Mass Storage' or 'Serial Mode' (Mass Storage is what you want), start Sentinel.
In Sentinel, click on the drop down Scanner menu at the top of the screen.
Choose "Clear User Data" from the menu.
You'll get a pop-up window, which likely will show nothing to to connect to.
Select the box that says 'Show all drives'
You should then see a drive letter that will be your replacement card.
Choose that drive & let Sentinel perform the setup.
Once done, then select 'Write to Scanner' to send your favorites lists to the radio. Write to Scanner is also under the drop-down scanner menu, or you can on the small icon that is under the "r" in Scanner at the top of the screen. After this is done, the scanner will have the database, as well as any Favorites lists that you have created.
If the scanner is connected to the pc, be sure to 'eject' the card correctly in Windows. The same 'eject' process should also be employed if using a card reader. Once you get the 'safe to remove' blurb in Windows, you can disconnect the scanner from the PC, or pull the card reader out of the USB port. Once the card is in place, the scanner should boot up & work.