We had a similar problem on our Candy. About two months ago we noticed a large slab of ice on the back of the fridge section and the vents in the freezer also blocked with frost/ice.
Performed a manual defrost but fridge back freezing up again.
Then a couple of nights ago noted the ice starting to melt but then had the orange "super" light flashing. Mains reset didn't clear but turning the thermostat to zero then back up again cleared the fault.
The appliance is six years old so the only real conclusion I can draw is that it is reaching the end of its useful life, despite our previous FF (a LEC) lasting 15 years!
BigVern
January 2009