When it's time to hang Christmas lights, you may notice a few dead bulbs. Repairing these lights won't be easy, but with a little determination and know-how, it can be done.

To fix burnt-out bulbs, untangle all string lights and check for frayed wires, damaged sockets, or broken bulbs. Discard any damaged bulbs, and then replace them with spare ones.

Most new packs of Christmas lights come with a replacement fuse—which should give you a clue as to how common fuse problems are with these things. A blown fuse also causes the entire string to ...