how to fix my fridge, zanussi/electrolux frostfree znb-4051s?

Can you hear the motor running.
If so it is trying to cool.
If not. Well other.
If not could be problem with thermostat.
If does, Could be problem with refrigerant charge. BUT as they are sealed unit. you might have a hole in the system, OR the defrost heater is staying on. IF you have one, If you have defrost heater, (Located behind panel inside unit) unplug it. If that fixes it, could be relay or other on pcb. . If no defrost heater, System fault. Depends on if and where leak, If so Replace unit

SD
June 2012