How to Troubleshoot a Fuse Box | Hunker Locate the appropriate fuse in the fuse box. Fuses should be labeled. Identify the blown fuse by inspecting the fuses visually. Fuses in all devices, not just household fuse boxes, work by having a wire overheat and melt, causing a break in the circuit if the circuit becomes overloaded. How to Replace a Circuit Breaker Fuse | DoItYourself wwwyourself››Electrical Tools & SuppliesFollow these steps to replace a circuit breaker fuse. Step 1 – Open the Fuse Box. Wear rubber soled shoes and ensure the floor beneath the circuit breaker box is dry to minimize the risk of injury. To start, remove the circuit breaker box cover by unscrewing the corners with a screwdriver.