All the replies so far are right on target. If this indeed happened during a database update, you should just get an older database or new copy on a new memory card and try again. When you install a database it deleted everything in there and installs all new files. As another user mentioned, you can do a bitlog and CRC test of the files too.
If it is NOT the database that's the problem, you could have a corrupt drive on the screen. That's a much bigger job to fix, and you'll end up taking the screen apart to fix it. I highly caution anyone who has hardware issues against sending their screens anywhere for support. If you have any damage in shipping, insuring it won't be enough, because there are plenty of parts that you simply can't get anymore. So any time you work on them or ship them, you risk a forced panel upgrade.
I always have the same advice for people who wish to continue using those Chelton screens.
1) Have at least 10 or more spare memory cards on hand. They fail, and are not nearly as robust as current memory card technology.
If you end up with all of your cards destroyed, you can't update databases or even change configuration of the screens anymore.
2) Buy hardware spares. Spare screens, spare ahrs, spare magnetometer, anything that can go bad. The AHRS are expensive to fix and take time to do so, and the screens may not be fully repairable depending on the issue. So own spare systems, and start saving for replacements because they won't last forever. These were designed around the year 2000, and 19 years is much much much longer than the useful lifetime of most any computer technology.
Lucky they were way ahead of their time when they were built, because from a functional standpoint, they only in the past few years being caught up and passed by the other companies.
Also, as someone mentioned, I have a forum that you can join and post specific questions for that system on, and there are many Chelton users who can answer some of those things for you. CheltonEFISpilots.com