how to find the blown bulb in christmas lights

Good question! Finding a blown bulb in Christmas lights can be a little tricky, but there are a few things you can try. First, check for any obvious signs of damage or burn marks on the bulbs. If you see any, it's likely that bulb is the culprit. If there are no obvious signs, you can try using a multimeter to test each bulb individually. A multimeter will let you know if a bulb is good or bad. If the bulb is bad, replace it with a new one. If that doesn't work, you may need to replace the entire string of lights.