Hi there, I have a liebherr model K3660 serial no - 24.710.521.6. Has worked perfect for about 5 years but over past few days has started freezing everything. The fan at the top still spins okay and stops as you open the door. I presume the fridge has a faulty sensor which is causing the compressor to work continuously. Where are the sensors / thermistors on this model and is this the likely fault