LED Light Pulsing


21 Feb 2020
Between Japan (Kyushu) and the UK (East Anglia)

After taking my final tank photos this morning, I put everything back to normal. However, I just noticed that the LED spot light is pulsing. It's on a dimmer switch at about 50%, but it pulses between 50-100% once or twice per second. It's even more noticeable when I dim the light right down.

Any ideas why it's started doing this? Is there something I can do to fix it, or is it just a cheap Chinese knockoff? It seems pretty solidly built.

>Here's the link< to Amazon.

Thanks :)


16 Apr 2015
It could have several causes, Overheating, due to incorrect power supply or faulty heatsink connection. The LED isn't dimmable or the wrong dimmer is used or dimmer device fault if it is an electronic PWM device. If it's a PWM dimmer see if it comes with a reset button, or plug it off the power and plug it in again. Or it's a faulty build-in driver...

It can happen to any LED, China knock-offs actually don't really exist, for example, Phillips Hue LED's are produced in and around China as well. Could be bad luck having bought one made on a blue Monday...

In case it is the build-in driver that's faulty then see if the seller gives a warranty and if you still are within this period. I had the same issue with some china LED bulbs from Ebay. I contacted the seller, they asked me to send a video. And after seeing it they did offer a refund or a resend.

The LED's 50.000-hour life cycle statement is theoretical, in most cases, the driver doesn't live up to that and no driver means no useable LED. Since they come rather cheap it's always best to buy a spare bulb with it.

Other useful tips, always make sure the LED is labelled Dimmable and if so ask the vendor which type of dimmer is advised.
We have different types of LEDs and drivers, requiring (compatible with) different types of dimmers.

Ps, noticed the Amazone link a tad late, but it's in Chinese/Japanese... :) I can't read... Looking at the pictures it looks like a warranty case. Hopefully.
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