This book has been written as a guide for people who might be called electronic problem-solvers. It concerns itself with the practical aspects of servicing audio and hi-fi equipment and its peripherals. It is not, of course, possible to cover every type of circuit that has ever been produced nor every fault symptom. Many suggestions and approaches in the text may be different to those employed by readers at present, but all the information here is based on practical experience. The principle is to allow the reader to develop from a sound base. Once in possession of the basic skills of diagnosis testing and repair, new and different products and technologies are not too difficult to adapt to. The idea in this book is that readers can associate with the examples and terms used and be conversent with electronic and electro-mechanical principles as used in domestic audio and hi-fi units. The book will not transform a novice into a senior engineer, nor is it a do-it-yourself guide.