It was so frustrating this year to pull our Christmas tree lights out of the box and find that 4 of them were only halfway working. FOUR!
What do they do in the box all year while they sit there, that would make them go bad? And why does only half the strand of lights not work, while the rest does?
You might be wondering the answer to these questions too, and I'm happy to tell you that I found the answer.
Well, to be 100% honest, it was my wife who found it by bringing home a Light Keeper Pro for me to try on the lights. Sure enough, the first attempt on the first strand I tried (the one that was on our fully decorated tree) was fixed by this handy device that you can find at Amazon for under $20.
How does it work? It turns out that one of the most common causes of light set failure is a malfunctioning bulb "shunt", that can be cleared by being zapped with a slight electrical pulse. I have no idea what a shunt is (I'm not an electrician) but the Light Keeper designers do, and it really does work.
Not all light strands have misbehaving shunts though - some just plain have bad bulbs, which is another thing the Light Keeper can check for. It has the ability to sense voltage through each bulb just by pointing it each bulb.
If the tester beeps, then the bulb has electricity flowing through it. If it doesn't beep, then the bulb is bad and needs to be replaced, which was the problem for the second strand of lights I fixed.