The bulb tester, built into the top of the lightkeeper pro, offers a third way to repair.
View Christmas Tree Light Bulb Voltage
Pics. If you only wanted to use 1 light bulb it should light up at around 6 dc volts. I've not seen many strings of christmas lights with a control box.
How To Fix Christmas Lights The Home Depot from contentgrid.homedepot-static.com
Wireless christmas tree lights are powered by a magnetic field. Christmas lights use very little power. Most mini bulbs are wired in series and just plug in.
To anybody looking for bulbs.
Don't install your lights on trees that come in contact with power lines. Leave them on while you work so you can see how they look on the tree, and so. They don't burn out, like other bulbs; I do my tree like this every year!