Don't have a 998, but have a 798. What are you seeing on the DI screen? If I'm not mistaken, the DI is a processor generated image from the data off of the SI. If the DI screen is completely blank, I would set to factory defaults and reboot and see what happens. If still the same, I would software upgrade the unit. You can do a snapshot of the screen and put it up. When you get to the main menu screen, scroll to the right and when you get to the last menu option, it should give the option to turn snapshots on. After it is turn on, you can hit mark and it will make a snapshot and save to your SD card. You can then up load to the forum so it can be seen by anyone trying to help. The tech forum could probably help with this. There are some smart people up there as well as Humminbird Greg, a hummingbird rep who stops by pretty often. If the DI view is just not available, you can set user mode to advanced and then turn on and off the views you want in the menu. Hope this gets you started in the right direction.