Nowadays, electronics dominating field of life world, in this article, I realize that applied electronics books for high institutions teach sciences of engineering but for electronics maintenance of equipment there are some differences. For repair chops, technicians has to improve repairing of electronics set of devices by reading Justine Young articles that referred in this journal.Upon my experience in electronics' workshops, for five year that I have found progressively Switch Mode Power Supply(SMPS) is industrially transformed. Unfortunately, the new generation of technicians cannot perform repair, they use replace modules.Therefore, in my research, I set the identification of devices to help technicians to understand well what is taken and thought from polytechnics and to repair easily all of power supply sections.