Yoyofactory Kui LEDs are flickering and fading?

Hi guys,

I recently bought a YYF KUI and I have a problem with the lights.

I noticed that the light in one of the metal cups was flickering and fading faster than the other side. To be a bit more specific, the test I did was throwing the yoyo, stabilizing it with my finger nail, and then looking at the lights: with stable rotation one of the lights seems to have problems. I though it was a battery problem, so today I new ones and changed them. I used a suction cup to remove the plastic cup, in order to avoid scratches. It seems the problem was not the battery and I did not want to work deeper into that in order to not damage it.

Did it ever happen the same to you? Any idea?

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I don’t know what the switching mechanism is on the KUI, but it sounds like one side is requiring too much centrifugal force to engage. You may just need to contact the store, or YYF…

Keep playing with it for a bit though. It may even work itself out.


If changing the Batteries did not work then it might be a problem with the lights themselves. Did you buy it from us? If so give us a call or send an email and we can take care of it for you.

Also for future reference on the KUI - There’s a small hole on each side (under the axle) where you can poke through with a hex key to pop the caps off.

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Can the yoyo being to tight or to loose make the lights behave differently

No, that shouldn’t matter. The yo-yos spin forces the electrical switch closed and it should light up. What are you seeing?

The lights go light to dim the it flashes

I had an issue with my light up fhz. Don’t know if it is a similar design, but in the fhz, there were little strips of metal that are very flexible. When the yoyo was spinning, the strips would be pushed down/outward and touch another piece of metal to complete the circuit and send power to the lights. On the flickering half, I noticed the strip of metal rested a little higher when not spinning. So I VERY CAREFULLY bent it downward just a bit. It worked.
I no longer have the fhz, but if I need to clarify anything I will do my best.


On both halves or just one? Centrifugal force is what’s triggering the lights to turn on, so as the yo-yo slows down this will happen normally. If this is happening on a strong throw then there may be an issue.

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On just one side can I return it to get a new one

Contact YYE directly if you bought it from them and they can help you out.

or me,
Ill send a new curcuit board


I’m actually seeing exactly this “one side is dimmer / activates less reliably” on both Kuis I own.

Is this something I can fix @yyfben2 or is circuitboard swap the only way? It looks to me like the gravity (centrepital force or whatever) activation switch is an all internal kinda deal, it doesn’t look tweakable to my eye.

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Same here. Solved issue by switching over to Aurora. :smirk:

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But my Aurora had one dim side too!


Swap halves and see if that works?

Too late sold it! The dim side annoyed me too much.


Have you tried replacing the batteries?

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Board swap recommend

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Board swap recommended over battery replacement? How many TV remotes do you just throw away?

Anyway - Yeah, we can definitely replace the boards for you, that’s usually the second option… Feel free to send me a PM and I can arrange to get new boards shipped out.

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Both of the single color version Auroras I had did that but both of the multicolored ones I got are STRONG and consistent.