Just to confirm - it worked for me. Same problem (Indesit was only a few years old), and it was clicking.
The card is located at the top of your fridge; unplug the fridge from the mains, open the door, and then take the two screws on the left and right out (behind the little plastic covers); they hold the top plastic cover in place, behind it you will find the card that is clicked in place. Just check that you unplugged the fridge from the mains, then detach the wires unclick it from the front, and click the new card in...
Didn't find the card cheaper than 40 quid, the part number is C00274387, found it amongst other places on
https://parts.indesitservice.co.uk/indb2c/catalog/setCurrentItem/(isQuery=yes&query=*%24%24BAN12NFUK%24&layout=6_1_62_63_5_2&uiarea=2&ctype=areaDetails&next=seeItem&carea=%24ROOT&citem=00000012080000000120)/.do
Henk Muller
November 2010