LED Bulb burnout - what fails inside?
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- เผยแพร่เมื่อ 16 ธ.ค. 2022
- Analysis of 22 LED bulbs that burned out to find the most common point of failure.
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So... Back around 2014 Energy star changed the rules for getting the energystar rating for LED bulbs. They reduced the required heatsink with the idea that the energy that goes into making the heatsink was not ecological. The result was that all the prices of the bulbs plummeted and now here we are with bulbs that dont last very long. My experince is that they last one to two years. The manufacturers are driving the snot out of those poor LED's without enough (any?) heatsink. - At the same time the efficiency of the LED's generally goes down with how hard they are driven (Check your data sheets). The modern world leaves us with products designed only for cost of production, and has no desire to make a product that lasts. Just buy a new one and throw the old one out - because that is ecologically desirable? An LED bulb could literally last a lifetime if designed properly - I would guesstimate that it would cost 4 to 5 times as much to produce (I used to design LED bulbs in a previous life).
Well, there are 'Dubai style' filament LEDs which don't have any heat sink but last very long.
Yes I agree it's revolting.
I do harvest parts for my prototypes.
It's a token gesture....
It sucks with expensive outdoor lights. The LEDs fry, and I’m glad I am handy enough to replace them.
Capacitor only rated for 200V. Should be at least 370V. And it's trapped inside the hot aluminum base cup.
@@marshmower- the mains voltage over there is only 110V, so that's about 157V peak to peak. That is well within the safe operating range of a 200V capacitor 🙄
Great vid. I have also spent a bunch of time working with LED bulbs. I created a process to fix them. I can fix several of the type I use in 15 minutes. However, if they have very much use on them, it may not be worth it. While the bad parts/ LEDs are easy to replace, the stress that the other parts have endured will create the next weak point.
I have gotten into the habit of modding new bulbs to run on less current, idea via BigClive. This step really makes them perform like LEDs should. It's too bad that bean counters have reduced them to rock bottom price. It's causing a lot of frustration with an otherwise excellent tech.
You’re right. Nearly all failed LED bulbs are tossed. Only someone as brilliant as you would consider why they failed. I learn a lot from your videos. Please don’t stop.
Your analysis makes sense, especially with regards to the driver and capacitor failures. FYI, I bought a couple of the original "corn cob" LED lights more than ten years ago. They run all night, every night, and they're still working. Each bulb is composed of a network of small LEDs wired together, in conjunction with a clever passive resistor network to limit current. No electrical components other than resistors and LEDs. One other note: About ten years ago I installed a whole house surge suppressor. It was a Black Friday special, that cost less than $100, but took some ingenuity to install. Prior to installing that, I had a lot of CFLs that would burn out prematurely, but all lasted MUCH longer life after the suppressor install. Most of my CFL bulbs have since been replaced with LEDs, and I haven't had a single LED bulb fail on me since.
My favorite topic. I have many as well. I've bridged dead chips with resistors for a new life. Reportedly the driver is supposed to adjust, making a resistor unnecessary, but it seems to depend on the driver design. I've found bulbs "not for use in enclosed luminares" last a long time if you remove the diffuser. Like everyone's been saying, it seems to be a heat issue no matter how you slice it.
Great video. Most of the time the problem is driving the LEDs close or above the maximum rating and the heat it generates. That is the real problem, heat destroys everything.
What I did is take a few cheap Ikea bulbs of the same type and remove the enclosure and use one driver to drive all of the LED panels (parallel). Result: The current provided by the driver is now divided by the number of attached LED panels, less heat, same overall wattage and more spots/points with light. The reduction of current result in a slightly lower brightness of the panels but will be compensated by the amount of panels and the wider angle light can be produced. I applied this method in the kitchen, living room and a workbench lamp with great results. Did this a year ago and still running fine. It is also a great way to save on energy. For example 5 LED panels with 5 drivers = 25W but in this configuration it is only 5W (the current is limited by the driver).
Another way is to use a (correct rated) capacitor (as 'resistor') in series with the lamp to limit the amount of current (power) it can use however the downside of doing this is that the lamp will be less bright. But the amount of heat it will produce also decreases which is good. This will increase the lifetime of the bulb.
Last option is the "Big Clive" method to change the current limit resistors on the driver of the LED panel but this requires knowledge of the configuration and how to change it.
All these methods extend the lifetime of the lamps/LEDs. You will be surprised how sensitive these LEDs are and reducing the current take away the heat dramatically but still keep a plausible amount of light.
Great summary. LEDs and LED bulbs have come a loooonnngg way from 1947 when they first discovered semiconductor properties. I saw a movie by one of the transistor inventers that showed the various phenomenon that semiconductors had. One was when you energized a semiconductor material it would emit light. In the video they used a microscope to show the little tiny light emission form where a wire contacted the semiconductor chip. That little flicker grew to what is now lighting buildings and streets. They have come a long long long way.
We’re on that same wavelength again. I literally tore one down yesterday and concluded bad solder joint on the input of transformer. Also I have another where the pcb Traces cracked. By design of course.
Other then that.
Everything is Sine.
Interesting to see... i am caretaker on a business property.. I had alomost all LED bulbs failed after 3 month or less...no matter what brand. Then i started to put a capacitor in series.. 1 or 2 microfarad..usually. A 12 Watt Bulb goes down to 3 Watt with 1 µF but..surprisingly, the light output is just a little bit less...not by much. Since than, i had no more burned LED bubsl, so far. They run way cooler and last longer... My conclusion..they are definitely ment to fail right from the factory. Greets from Germany..
The human eye has (approximately) logarithmic response to illumination levels. It also contains an automatic exposure compensation device called the 'Iris'.
It takes about 10 times the illumination to double the perceived brightness. So doubling the light level makes no visible difference, which then quickly gets compensated by the iris anyway.
It works the same way in the other dirction too. For this reason, a reduction in light levels will not change the apparent "brightness" to a significant degree.
...
HOWEVER in a commercial premises the lighting levels fall under various laws, standards and building codes. Especially in Germany, where "all rules must be obeyed".
If there is any accident or incident where visibility might be the cause, then you are in a world of problems if the insurance companies find out that you deliberately reduced the lighting levels below the respective minimum standards.
In this case, there is no such policy on this property...The Lights are on all night...just to keep burglers away. I i need mor light, i use two of the "pimped" lamps instead of one untampered.. Works great ;)@@johncoops6897
They overun L.E.D.s (too much drive current) and not enough heat sinking.
I bought star L.E.D.s off of Ebay that are 3 Watt or 5 Watt and are supposed to be run up to 500 mA.
Truth is they won't last more than a few months even running at 350 mA. I have a string of them up that runs across my privacy fence. Cool White ones than run on a timer all night. I finally backed them down to 250 mA and they finally are lasting now some of them have been out there about 3 years now. They are still plenty bright at 250 milli Amps. Like you John I also noticed when they would go out when I was running them at 350 mA, it would always be the next time the timer turned on for the night after turning off that morning with them all working and one of them would be out causing the whole string to fail especially during could winter nights.
So I also believe it's a heat cycling related problem. The ones I'm running are the star L.E.D.s. Under running them at only 250 mA seems to have fixed the problem.
They are able to produce LED bulbs that almost never fail (Philips did a custom order for some Sheik in Dubai (the Dubai Special Edition LED Series). But they won´t sell them anywhere else in the world except Dubai (for the obvious reason that eventually nobody would need new lamps anymore). The main principal is that the LED´s work at a significant lower power (lower temperature), the other is using ´redundant´ components on the PCB. If one might fail, the other keeps working...
If you crack off one of the parralel resistors feeding the currrent control pin on the driver chip, the leds will be driven with a lot less current and the bulb will last a lot longer, Bigclive does this a lot.
Thanks. I replace a lot of bulbs in exit signs and would like one that last a lot longer.
I just found these Great Value led bulbs and the Aluminum pcb is only housing 9 LEDs. Nice. I hope to find more like this. It lasted about 2 years before the transformer disconnected itself.
@@MagruderSpoots here is an interesting video to make bulbs last longer "Hacking an extra trashy Poundland LED lamp (with schematic)" it is a simple hack by the youtube chanel Bibclive.
Keep in mind that this works only for the bulbs with the linear current regulator chips. The PWM type drivers may need another method to hack. They also now make 25w (equiv) bulbs that use only a couple watts and run very cool. For some reason A19 style 25w equivalent LED bulbs were hard to find.
@@MagruderSpoots- you should never reduce the current in Exit lights, as that also reduces their light output.
The performance of Exit lights is tested and certified, and this determines their spacing distances. The ENTIRE building compliance relies on the "rated" performance of the LEDs.
...
By changing the LED type or output, you nullify the building's compliance. Therefore there is no point in having the system at all (there is no such thing as partial compliance). You might as well just switch off the Exit lighting system, as that will save you on electricity and maintenance.
Hi John, wanted to wish you Happy Holidays and thank you for all the great videos you've given everyone over the last year. My interest in electronics would be greatly diminished without your help.
Thank You and Happy Holidays!
A good explanation of failures mechanisms of LED bulbs. It matches my own experience and those of a couple of other people I know, and also of failures on-line (BigClive). The LEDs have a tough time as they are usually over run, and suffer a lot of heat stress. The light and heat from the LEDs also degrades the phosphor over time. You can usually tell bond failure because the LEDs will start to flicker randomly, and then get progressively worse. They will often work until they have been on for a while, before they've had a chance to heat up (sometimes it's the opposite: won't work unless warm). Three failures myself: One was a bad connection in the base and another looks like cracked solder joints on the LEDs from heat cycling. The third went back under guarantee (premature failure, but it almost reached it's guarantee period, only missing by a month) as it was an expensive shaped fluorescent replacement, so no details on the failure mode, although it did glow extremely dimly in the dark, as if something went very high resistance.
And those LEDs would fail less often if they were run at lower currents. I haven't purchased any in over a year, but the bulbs I've seen were still pushing the currents higher than optimal in order to reduce the number of emitters and thus the cost. There remains an incentive problem with LED bulbs, in my opinion, as fewer emitters running at higher current saves the manufacturer money up front while also increasing repeat sales via premature failures. More failure = more profit.
That incentive might be offset by brands looking for loyalty, but I notice that the most popular bulbs on Amazon are generic brands that simply don't care about loyalty as they'll introduce the same bulbs under a new brand name next week :(.
As most of us know, BigClive popularized a method for dropping the current in half by simply removing one of the 2 "averaging" resistors that set the constant current on the driver chip. I do this for all of my bulbs except for some of those that have secondary driver boards under the LED board as that becomes much more difficult.
In my case, the bulbs with a separate driver module included twice as many emitters for the same wattage already, BUT the packaging claimed *half* the lifetime as their brethren running at twice the current! I see no reason why that would be true and it's just plain weird; the bulbs with twice the emitter current were being sold as having twice the lifetime :|.
The claimed life on LED bulbs is meaningless as manufacturers have no obligation to meet them. I've always been a light bulb geek, I've always bought the bulbs which are underrun. I've never been a big fan of surface mount LED bulbs though all of my bulbs are filament LEDs and I've only ever had 1 fail in the 8-9 years I've been using them, and that failure was within the first week of use so I got a free replacement under warranty.
All the light bulbs from IKEA that failed at my home had led's burnt
I wonder if the switch to glass envelopes on LED bulbs is to stop people from repairing them?
My thoughts exactly. 👍
The LEDs are usually connected in series so if one of them burns out the whole lightbulb won't work
I take them apart and bridge the traces of the burnt led together and it works for another year so i don't waste my money buying another lightbulb
great stuff
Thanks
I've owned LED bulbs since 2011. (Paid over $30 for my first one!) I've had a few fail in my house early on.
About 80% of my LED bulbs are smart bulbs made by WYZE. They have good CRI and great color saturation and whites.
My nephew used to complain that his would flicker. He buys the cheapest stuff. I found out a way to check for flicker. I used my iPad camera pointed at the bulb and looked for flicker in the screen. I had only one that flickered, the rest must have excellent filtering.
I like the bulbs where there are 2 or 3 current setting resistors. I just break one off with heavy duty tweezers, instantly drops the power use in half or 2/3
Great info !...cheers.
Great idea for a video. Almost all mine fail at the dropping cap.
I, too, have a box of LED bulbs from my parents 🙂 One day I will go through them but many have the telltale black spots on the LED's.
I've had LEDs that have lost it forever and are still working I have one lights of America cool white LED has still working and then I've had other brands that have failed I even had a few fail during a power surge
> a few fail during a power surge
That's the capacitor.
nice video
Ive been using filament LED bulbs for nearly 10 years and not had any fail apart from one that blew within 1 week of buying it, I got a free replacement.
I reckon its because every single bulb I bought gets 130+lm/w. From day 1 I refused to buy any that was lower efficiency... So a bulb that produces 806lm should use 6.2w or less. LED filament bulbs have been falling in quality since day 1 though. The early 6w 806lm bulbs I have have 6 filament strands, the same supplier now sells them at 6.4w and they have 4 filaments about the same length as the previous 6 filaments, I flat out refuse to buy them.
My new favourite is the LAP 3.8w 806lm bulb with 8 filament strands (212lm/w).
I'll have to check on those LAP 3.8w bulbs. That is impressive efficacy.
@@JohnAudioTech I live in the UK and the LAP 3.8w 806lm warm white bulbs are £5.50 in Screwfix. There's also an intergral max efficiency surface mount bulb rated 3.8w and 806lm for the cool white varient (the warm white is rated 4.3w and 806lm), they're £4.98. Philips have just started doing an ultra-efficient range that are rated 4w and 840lm (210lm/w) but they're around £12 each, I haven't tried them but I can imagine they'll be available worldwide?
Whats interesting is new bulbs out where the :EDs are placed directly on a alumina ceramic heatsink and the body of bulb is where the driver sits. They stay cool and the ceramic heatsink does not expand and contract.
Noticed a lot of them use a soft rubbery yellow goo instead of hard epoxy, guess I'm thinking of COB units...
I thought the same until I investigated these small SMD LEDs and it turns out to be a hardened epoxy like resin. All of the larger COB LED seems to use the rubbery silicone material that also has the phosphors mixed with it.
My understanding limmited as it is of LEDS is that once they are burnt they are out, No flicker no coming on and off or flickering before burnout. So I assume that if one of these bulbs is flickering before complete outage then it would likely be a driver falirue of connection failure?
interesting analysis. i wish they came in glass metal packages to reduce plastic wastage.
Interesting
hey John, what brand are those glass good PF, 95 CRI 4000K bulbs? It has everything i need!
TCP brand. I bought them at 1000 Bulbs.
Less powerful LEDs fail less often.
I'm getting a BUNCH of them that start flickering after just a few months.
John e amigos, aquilo no Brasil as lâmpadas vinham com os leds sobrealimentados. Certa vez medi um led de 3v, e ele estava com 3,7v. Agora trabalho nos resistores de saída para os leds ou nos resistores de controle de amperagem nos circuitos integrados. Saudações.
They over drive the leds with too much current
What's a Cdpdcitor?
😂
I think the fastest way to "recover" most of the bulbs is with a 2200ohm 3w resistor and a diode (FOR 110/127V!).
What causes them to flicker?
You should try watching a video before asking silly questions about it. 🙄
They fail because the leds are over driven (planned obsolescence), but you can fix this by opening a new light n remove one of the usually 2 current sense resistors on the reg chip which lowers the drive n yes some of the light level but they won't fail as designed, I have proven this over many yrs!
They are made to last over 10 years…. NOT
Where is Snickers?
Sadly, he passed away a year and a half ago.
@@JohnAudioTech I'm very sorry. He will be missed
2+6+2+14= 24 Not 22. Just a heads up