liebherr fridge/freezer wont defrost

[buildwise]

i have a Liebherr cnes5056 fridge freezer about 4 years old and all is ok apart from the fridge which has stopped defrosting. it has duel compressors and controls. any one got any ideas please ?

[abdulazman]

Try replacing your defrost timer.

[happy]

its likely to be the evaporator sensor, its quite a common fault

[buildwise]

its likely to be the evaporator sensor, its quite a common fault
thanks. would you do this before replacing the defrost timer ?

[happy]

it has no defrost timer - its fully electronic