In this video session, we will be discussing about electronic components called fuse. A fuse is an electrical/electronic device that protects the circuit from over current. The principle of a fuse is based on the heating effect of the current. There are many types of fuses like AC fuse, SMD fuse, rewirable fuse and enclosed type fuse used in electrical and electronic devices. To become a hardware repairing expert, knowing the features of this component, and its testing procedures are very important. In this session we will learn what is a fuse, how does it looks like, the architecture of different fuses, the marking of fuse on PCB and circuit, the work of fuse, how to Identify bad fuse, and testing procedure of a fuse using a multi-meter.