All I can say is the check the solder connections where the display meets the board. other than that you will be out of luck unless you can find a detailed drawing. But that is highly doubtful. if you do Let me know.
All I can tell you is that there is no published information on what you are looking for that I know of.
You might want to contact Wild Bill http://www.webwarden.net/wildbill/index.php
He fixes the Z31 Digital dashes and might know of a fix for yours.