LED Chassis fans have lost their brightness over time..why?!?!

[Gerard Vincent]

I built my system using blue LED chassis fans ( 4 x 200mm) & (1 x 120mm) all by Cooler Master. Put them in a CM HAF-X case. Looked GREAT! I've connected them all to the Motherboard and used Asus AI-Suite as a software fan control. The LED's dimmed as i dropped the fan speeds as expected and stayed bright at 100%. Everything has seemed to be working fine but over time the LED's seem to have dimmed. I usually run all my fans at 100% since they are so quiet and I like the light they give off. It's been a year now and i swear the brightness in them is down to about 50% of what they were. Has anyone had something like this happen to them? I checked to make sure that they were getting enough power, I even bypassed one of the connections off the MOBO and connected it to a MOLEX adapter, still the same brightness. I purchased one new 200mm CoolerMaster Fan and it is twice as bright as all the others, no matter if it is connected to molex, or the MOBO. Why are all the other fans so dim?

 

[synphul]

Have you tried cleaning them? Dust could have settled into the small holes where the led's shine through around the fan shroud. Even a light layer of dust might make them 'dim' or 'hazy'. If they're clean, it could just be cheap led's slowly dying and losing intensity. I'm not sure if undervolting (speed control) of the fans and subsequently the led's has any effect on their lifespan. I don't think they use very high quality led's in fans.

 

[Gerard Vincent]

I keep the entire system squeaky clean by blowing all the dust out a few times a month with an air compressor. I don't think its undervoltage because when I hook into a full 12V molex, they are still quite dimmer than what they used to be. Do fans go bad that quickly?

 

[synphul]

I really don't know in terms of the leds used in fans. I just meant maybe it's possible that running the fans slower (if they were slowed with voltage by undervolting) for some time that it could have possibly weakened the led's. So now even at full 12v they're dimmer maybe. Just guessing. If the led's are exposed enough maybe try a cotton swab with some rubbing alcohol and try to gently rub in the holes where the fan lights shine through.

Even blowing out dust won't get all of it. It removes surface dust but may leave a thin layer on the bulbs. For instance, when your case looks a little dusty, try blowing it out like you normally do. When you're done, take a small area like the floor of the case or something that's not a component and wipe it with a paper towel dampened with a little alcohol and you'll probably see a little dust/dirt that gets wiped up. I'm not 100% certain, just speculating. If none of those things work then I'd just assume lower quality leds in the fan and they may be prematurely burning out/dimming.

 

[Karadjgne]

An led is nothing more really than an anode/cathode and the light you see is the 'spark' of electricity between them. The color of the spark is determined by the frequency of that electric spark. Being 2 separate poles not joined by a wire like an incandescent bulb, that spark gradually eats away at the anode, the exact same way as in a spark plug center electrode. This is ultimately more evident in leds that are made with ultra cheap alloys that contain more impurities in the metal, the molecules of which are loosened by the current of electricity.

So technically, yes, it's highly possible that leds can loose some intensity over time/usage, until the gap is sufficient to cause too much resistance to work, raising the amperage through the led, which eventually burns it out.

The only solution to the dilemma is replacement. Either the fan as a whole, or the leds with higher quality ones