Unfortunately, the bypass wire doesn't actually always burn out to make the rest of the lights work. There is a device called a LightKeeper pro that sends a la

Unfortunately, the bypass wire doesn't actually always burn out to make the rest of the lights work. There is a device called a LightKeeper pro that sends a larger "zap" through the string to encourage the needed bypass wire to burn out. Its saved me a bunch of time figuring out which bulb was bad in a string of lights.