Problems with miniature lightning strings
When a string of mini lights stops working you can try some methods to troubleshoot the issue. You don’t need to consider that all the lights are broken or that there is something wrong with the wiring. If one light bulb breaks it will cause the entire string to stop working.
1. Try to find out if there are any burned-out bulbs and use the replacements that you have to fix them. Identify which identical sets work by plugging them into an outlet and see if they work. From the set that doesn’t work, take each bulb and place it in the set that works by replacing a random bulb. If the set continues to work than the bulb is good. The one that prevents the good set from functioning is the broken bulb. This one will need to be replaced. This is a hard job and you need to be patient until you find all broken bulbs.
2. Check the fuse with an ohmmeter to see if it works. To prevent the wires from getting damaged the fused are usually designed to melt down. If you have many strings of lights than the fuse is overloaded and it becomes a fire hazard. If you identify that this is the problem then replace the fuse after you remove the plug cover.
3. Check for shorts and exposed wires in the light string. Use electric or insulated tape to wrap the exposed wires but don’t do anything until you unplug the light string.