If you have a blown fuse, it's important to replace it as soon as possible. A blown fuse indicates an overload on the circuit, and replacing the fuse will help prevent any further damage. Here's how to replace a blown fuse:
First, identify the blown fuse. You can usually tell which one it is by looking for the burnt-out element. Once you've found the blown fuse, remove it from the holder. Make sure to note which way round it was inserted so that you can put the new one in the same way.
Next, insert the new fuse into the holder and ensure it is fully seated. Once the new fuse is in place, replace the cover and turn on the power. If everything is working correctly, you should see the lights come on. If they don't, check to ensure the new fuse is inserted correctly and try again.