Domestic Appliance Forum

I have an E-Nr.KK28E76TI/01, and it's showing a dash (-) on the right display, meant for the top fridge compartment. I try to adjust the level of the compartment, and the numbers change briefly as I choose the temperature. When I wait a few seconds, the display goes right back to the dash. How can I fix this? My food is getting warm!
The freezer seems to be okay, but will keep an eye on it anyway.