Light set failure can be traced to an interruption of electricity flowing through the light set.

The interruption of flow can be caused by any of the following:

1. A burned out bulb with a defective shunt inside the bulb, the # 1 cause of light set failure.
2. Missing or loose miniature bulbs.
3. A broken or twisted wire at the base of the miniature bulb.
4. Safety fuse(s) that have been tripped due to overloading current.

Inspect the light set for any missing bulbs or obvious connection problems. End-to End or String-A-Long Miniature light sets are designed to allow only specific number to be connected together. Most Manufacturers recommend no more than 3 Sets or 300 bulbs total be connected. Connecting more sets together than the Manufacturers recommend will cause the fuse to blow. This is most easily detected because all the light strings connected together will be unlit. If you know this to be the problem, visually check the fuses located in the plug of the light set located closest to the power source.