This work aims to develop a logical approach to fault finding, in the manner required by the City and Guilds Electronics Servicing course at Part II level and the appropriate BTEC units at Levels II and III. The book does not deal with equipment as such, but with the typical circuits whose fault diagnoses have to be mastered before full equipment and systems can be diagnosed. All circuits have been built, tested and measured under fault conditions by the author. There is also a selection of questions and answers.