how do you find burned out christmas lights

Well, it's not an easy task, but there are a few tricks you can try. First, look for the bulb itself. If it's blown, the filament inside the bulb will be broken or melted. If the bulb is intact but not working, try gently shaking the string of lights to see if the bulb loosens. If it does, try rotating it to see if it comes loose. If none of these work, then you may need to replace the entire string of lights.