Can you post the model number of the appliance please.
Is the freezer side still working ok?
Ok i think the fault will be the freezer evaporator will be blocked with ice. As the fridge section gets its cooling from the freezer if theres too much ice it stops the air flow into the fridge so the fridge doesnt cool down as it should so the temperture display only reads certain tempertures so if it goes warm then it doesnt read the temperture so goes blank like its done.
What you need to do is either fully empty the freezer and remove the rear cover inside the freezer and from there you wll see the evaporator. If this is covered in ice you need to use a hairdryer and melt the ice from there.
Then refit the covers and see how it goes from there and that should cure the fault.
But if you dont want to go messing with the covers then you need to empty the freezer and turn it off for 24 hours and leave the freezer door open.
This will allow the ice to melt itself behind the panels.
Then after 24 hours turn it back on and again see how it goes. Fingers crossed this will sort the fault out from there as thats usually what causes this kind of fault here.
Let me know how it goes.