KGU 34640GB/01. This FF had iced up evaporator with no fan action. All the heaters and sensors have readings through them. The display on this FF is only working for the fridge side, the freezer display does not do anything (no lights at all). I suspect the board but could do with some reassurance.
I would say faulty PCB IMHO 😉
Temp faults would cause alarm to sound and NTC fault/s would put appliance in a sort of fail safe.
Display LEDs should stay lit as they are merely temp settings and not actual compartment temps.