Check whether the device or circuit has lost power
Inspect the fuse for a broken or melted metal strip inside
Look for darkening, cloudiness, or burn marks on the fuse
Use a multimeter set to continuity or resistance
A good fuse shows continuity or very low resistance
A blown fuse shows no continuity or very high resistance
Compare the fuse to a known good fuse of the same type
Replace the fuse only with one of the same rating and type