LED Light Bulbs DO Burn Out!!!

Wow, who would've thought that solid state parts could ever fail.

Our problem here is that most lifetime studies on LED's are properly set up to predict the lifetime of just the LED. Most marketeers pounce on the 50,000 hour (almost 6 years) lifetime that a properly powered and protected LED can have to make a marketing projection. They often conveniently forget that unlike a filament, the LED cannot operate at the voltages and currents available directly from the power grid. So additional components are required to control the grid power to levels suitable to the LED. These parts typically do not have the required five to ten times longer lifetime of the LED to keep the LED as the weakest link in the longevity chain. Compounding this longevity shortening are two related critical factors. Since an LED is a very non-linear device, a marginal linear drift in the other components can dramatically increase the power drawn by the LED thus reducing its lifetime. Similarly power line transients from coupled lightning, electric motors and other noise sources may propagate through the non-linear response of the LED in catastrophic ways.

Oh, I forgot to mention that there are also pathetically made products out there. A few of the really poorly assembled products are good manufacturers learning how to make a new product. Most are scam artists looking for quick money. Likely these raconteurs are also making counterfeit parts on an adjacent assembly line. It looks like "Lights of America" fits the latter category.

".. these raconteurs are also making counterfeit parts .." But at least they'll be able to tell an amusing story as to why they failed. Ffej (who also gets caught by the crafty spell-checker)

YES!!! This is something that I have long squawked about but nobody seems to pay attention. I'm tempted to register just so I can give you a GA!

It's like a car salemsman pointing to one bolt and claiming that the car will be totally maintence free because that bolt won't fail for an estimated 800 billion miles.

On a related note, I've had Fluorescent bulbs fail similarly early. Not because of the tube itself but because of the electronics in the ballast failing. A similar thing may be expected of LED bulbs. The LED's driver circuitry will likely often be of the most primative and cheap design possible. Particuarly on the "mystery brands", but possibly on better-known brands as well. And even if it's well-designed there's only just so much you can do with a bulb-sized largely-unventilated package.

The predicted lifetime of an LED is based on its operating temperature. Some products on the market run much to hot to give maximum life. Proper heat removal from LEDs costs money and involves the use of fairly expensive materials. Also, you are correct about the reliability of associated drive electronics. Most circuits use aluminum electrolytic capacitors that have a failure rate about 5 times as high as a properly cooled LED. I recently received a magazine from Digi-Key by the name of Techzone Magazine-Lighting Solutions that describes most of the current engineering challenges associated with LED lighting.

History of LED development is full with the failure of solid state parts. The root cause is manual dispensing of die-attach adhesive which is

1. Non uniform lay down

2. Pore and porosity cause localized heating under pore and temperature gradient on the surface of LED chip

3. Poor wiring

4. Poor thermal management

Biggest in all of this from china is manual die attach of the chip which created a biased reverse voltage and that with localized heat makes temperature go as high as 125 oC

Degradation starts when you exceed 75oC and if you buy two LED bulb from china you will be lucky if the life is within 50% of each other and both combined last half of calculated life of getting bored with bulb which is about 10 years

I had hoped that people seeing the emoticon would recognize that I was being sarcastic with my first sentence. All components have failure modes. No component is immune to the inevitable effects of entropy.

Yes, temperature is a very critical criteria of an LED. When one carefully examines the Shockley diode equation this becomes obvious.

I have many CFL bulbs that have operated for a few years with no problems, so those seem to be much better than the LEDs. I'm just glad I only paid $6 for those LED bulbs, and not $50 for one of the higher wattage units!!!

If you have an application where every watt is critical, then LEDs would work, but realize that they'll most likely only work for a year or two before failure. Mine had been used lightly, so that was even more diappointing. In heavier use you may not even get one year out of them.

On a related note, I've noticed several Prius cars with burned out tail lights. I'd bet those are LED units with the same problem. I'll be avoiding any cars with LED bulbs thank you very much. Probably spendy to get fixed.

I make my own LED lights...

Run the AC into a bridge rectifier, and then the DC through a string of them - somewhat under driven.

Imagine 300VDC - string of 120 to 140 x 3V LED's... simple.

The eye has maximum NIGHT VISION sensitivity to I think either 505nm or 532nm light - which is a turquoise green light, one can see 2.5 times as well than with white light.

For center spot vision, you need a bit of red thrown in.

By using HIGH brightness green LED's, and about 20% mix of High Brightness red leds - one has about two and a bit times the amount of vision for the same lumens, and or every LED is under driven, and I am can just buy another bag of 100 or 200 LED's every 10 years.

The green light is interesting - kind of monochromatic.

Good lighting tho.

Bought the cheapest LED lamps around and then act surprised and irritated when they fail?

I would suggest you got what you paid for.

Same with CFLs - buy good ones from reputable suppliers (not Crazy Joes super special) and they will do much better.

No, I paid $6 each for them. That's a fairly expensive light bulb considering that the light is inferior to all other light bulbs. The real problem is that this will likely be a problem with even the most expensive LEDs. My point is that LED longevity is NOT what it is advertised to be, due to the electronics. AND that the law should protect the consumer by making the electronics modular and consumer-replaceable.

Consumer replaceable? Nobody repairs electronics today.

I admit that a year and a half usage for a LED line voltage replacement lamp is a very low lifetime. You did not get your money's worth out of those two lamps. But to leap from your bad experience to this being a likely problem for all LED lamps is quite a stretch. You may have simply been the victim of having bought two from a bad batch. Out of curiosity did you open your failed light to see what failed? That should have given you an idea how impractical it would be to replace parts. Your not swapping vacuum tubes out of a Zenith television now.

It may be a stoopid idea, I've not taken them apart to see what is in there, but I figured they might put all the electronics in a removeable "button" type of thing that you could just throw away and pop in a new one.

Hopefully I'm wrong about it likely being a problem with all of them, even the expensive ones. Time will tell I guess.

I still like the idea of LEDs because of the low power draw, but reliability is important also - hopefully they'll get better.

6 bucks apiece for a LED module was bottom shelf stuff!

The law of the market will take care of it - providing people are smart enough to stay away from the bargain box at the big box store.

How in the world would they make a LED package modular in such a cramped package. 99.9% of the people that buy them could care less about such a feature.

I have actually had multi-LED bulbs "explode" on me- the result of bad capacitors (one of the things the Chinese are noted for are their lousy capacitors). There is no way to tell what quality of electronic components are being used in the bulbs- even if the final manufacture is in the US or Europe, there is no guarantee that the manufacturer has not cut corners and used cheaper Chinese capacitors...

Amen!! I've had CFLs and surge protectors fail and when I took them apart they had electrolytic capacitors that had blown apart. All were made in China. One story is that some Chinese engineers(?) stole the tech data for manufacturing electrolytic capacitors from a Japanese company and took it to China. Unfortunately the data they swiped lacked some critical process details. As a result the Chinese market was flooded with crappy electrolytic capacitors and apparently still is.

cwarner7 11 I agree with you on the bad capacitors in electronics made in Asia. We have a Samsung LCD TV and Samsung Surround System both have had bad capacitors in the last month. Now although Samsung is a South Korea company I do not know if they Chinese capacitors.

The days are made in Korea and made in USA is in history book. We are in cost cutting and a global player to compete with third world which has no respect of product quality. We started buying globally including Toyota, Honda, Ford and Mercedes.

The inspection is not rigid and not 100% and result is random failure. This is same as in 50 and 60s my dad bought bicycle for us they manufactured in Japan and will not go one block in India then they made every thing in home and improved quality and then they started making with cheap labor now and you know the problem they are in.

This will happen for 20 to 30 years then China will be reliable and then they will be cost sensitive and new country will start making for China and we will go back to same cycle.

I tried to buy all component made in USA product and was not able to find any thing. Kemet capacitor manufacturer used to make reliable product in USA then shipped to Mexico and then was in process of shipping manufacturing to compete with China in China but half way market collapsed and they went through consolidation and I like capacitor from them and if they provide made in USA and not stamped made in Kemet

then feel comfortable. I am still trying to find how to work with made in china

Have you checked your power supply mains for correct voltage/surges?. Some things made in China are rubbish but the majority is 1st class- that is why western firms use Chinese goods in their products!. Any experimenter knows the fragility of leds to over-current. If you don't like electronics you will be mis sing most of the modern conveniences which could not work w/o electronics. As you have said most products can be fixed by r/p failed comp- so could your led lights(leds are cheap). So instead of bitching here- fix the c!@# of things!- you will feel so much better.

Actually I'd guess western firms use Chinese goods because they are cheap, not because of superior quality. Now-days quarterly profits are about all companies care about.

And, not long ago, most washers/dryers/dishwashers/refrigerators did not have electronics and they worked just fine. In many cases they worked for 20 or 30 years without failure. Try getting that out of a product with electronics. Ain't gonna happen very often.

You are correct re life of earlier white goods before microprocessors & micro controllers & associated electronics became the norm- but the price of these earlier goods relatively speaking purchase wise was way above present cheap crap!. Likewise, brown goods like tv,s- early crt sets were way better quality than present throwaway like plasma!!!- & here we are talking electronics!!. As Masy said- heat is the enemy- to electronic comp-esp electro caps!- crt used very little power ie heat v plasma!.

There will be no way except power-LEDs to give really good energy efficiency.

If you use CREE, OSRAM or Nichita you may have not very much trouble.

If you add a constant current souce (adjustable !) you are protected against drift and overvoltages from the power mains.

(HQI-light is pretty efficient too - does anybody have a comparison to LEDs?)

RHABE

This is true only for light engine then is the circuit board and control. We need to get out of poor quality (hard to do since we are now use to cheap stuff) components and get back to basic what you pay what you get. Do not sacify quality over cost then we will be okay

Same thing happened to me with IKEA LED night lights. When I opened them up I found a resistor open circuit. The resistor drops mains voltage to the LED driver circuit. The resistors weren't discoloured in any way so I think they died from a surge or spike on the mains input.

The resistors were replaced with 1watt, pulse withstanding resistors and the lights have worked perfectly ever since, (2+ years). It's always the support components that fail on these lights not the LEDs.

Heat is an LED's biggest enemy. Years ago before LED's became mainstream, I'd worked on a few custom bikes where we wanted to integrated them into the lighting. 2 issues, 1st not all LED's emit light in all directions, in our case a full 180 degrees. 2nd when grouped together too tight without a way to dissipate the heat they burn out fast.

Back then it took many phone calls to find LED's that could meet our requirements. Nowday's it's much easier to find quality lighting.

Also don't underestimate China's mfg. Sure many factories build product without adequate specifications or quality standards, but the ones that do are becoming a global threat. With China now starting the move into high end electronics, they're driving the manufacturing of all the department store crap we all buy into southeast Asian countries with even cheaper labor.

I sale LED light, I am italian and I live in china.

Before to buy my products I went to audit the company that I choose.

Here in China you can find many kind of manufacturing company...the good one where the price is " normal" and good quality. Others ( the same of the garage of my grandmother) where the price is very low. In this last one the quality is very poor.

I give to my customer 3 years of warranty, I am sure of the quality of my supplier, I chosen.

Who less spend more will spend!!!

Even given LED and other part's normal failure rates, your lights failed far faster than they should have, indicating either a design deficiency (e.g., thermally over-stressing a part), or a manufacturing defect.

It would be very helpful if you took the time to figure out how the circuits work (reverse engineering - draw out the schematic) and then determined the failure and its cause (or we can help with that).

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