Help! on defrost bimetal replacement

Hello, please to make a technical inquiry. I have a Daewoo refrigerator, non-frost, two door, model FR 3801 (110 volt, made in Korea). It works quite well
for about 10 days and then it starts to stop cooling because ice builds up on the condenser. A technician has diagnosed that I need to replace the defrost bi-metal.
But I have no information on the on/off temperatures of the original bi-metal. Neither are they written on the original bi-metal itself, nor is there any information
in the refrigerator's Service manual (much less in the User Manual). I would like to ask for help to either get that information,
or in case it is not possible to know if it is correct to replace it with another bi-metal and what connection/disconnection temperatures should have that substitute.
Thanks in advance for your technical advice, greetings, Eldis Viler