Answer to Question #4446 in Electric Circuits for roxy2441
why is it safe to repair a circuit when a fuse behind the short circuit blows?
If the fuse is blown, then the circuit becomes disconnected from a power grid, therefore, it becomes safe. But you need to unplug the power cord before changing the fuse, anyway. Also, don't forget to check the power supply capacitors and deenergise them if they are loaded when repearing the circuit.