I have found over time that my Servis M263 w Fridge/Freezer will stop working in both compartments, if I have left the press button switches(of which there are three,Max,Med, Min.) on too cold a setting,i.e. Max or Med,, when the ambient temperature surrounding the base of the f/f ,is also cold. This seems to have an effect on the condensation tube icing up. Simple answer was when the red light flashes warning of problem,switch off the f/f for a few hours, until icing up has melted ,and then switch on again, and hey presto! May need to rescue freezer contents if takes more than a few hours,but in five years I have done this (in winter months) three times and it works.
Ronedad, March 2013