It can be a source of frustration when the lights suddenly stop working, and you can’t identify any problem. When this occurs, the best thing to first do is to carry out some troubleshooting. You might discover the fault yourself without the need to hire a repairman. One of the major problems that are experienced is a lack of power. Determining whether the transformer is working is quite easy. To test whether it has power, plug in an electrical device and see if it powers the device. If not, then you need to get power to the outlet.