Tore Apart A Failed LED Bulb

[gusherb]

Yet another LED bulb has failed, 1 at home and 4 at work over the last week.

The one at home was a Cree 40 watt equivalent candelabra style bulb used in a hanging pendant over the kitchen island. It was two years old at best, run time maybe 5,000 hours give or take. Upon tear down there wasn't really anything evident except the board looked a bit scorched, particularly the transformer. There was a slight burnt varnish smell but not much. It first started failing by flickering then tonight went dead completely, which I believe points to a failed electrolytic capacitor. All of my LED bulbs have failed in this same manner.

 

[speedqueen]

Those who say LEDs are very reliable think of the diodes themselves but never of all the circuitry to run them, bridge rectifier, capacitors, transformer etc. LEDs can last 20000 hours but not LED retrofit bulbs with their compact power supply that allows for almost no heat dissipation. There are, however, true 20000 hour incandescent bulbs.

Some manufacturers have eliminated the electrolytic all together and let the bulbs flicker at 60hz.

 

[henene4]

IKEA retrofit bulbs over here are rated at 15k hours, our one lamp with build in LEDs has a 10 year warranty on the diods.

It is true that a lot of the dependency of the retrofit bulbs depends on thermal conditions, but for example BigClive on YouTube has torn apart so many cheep once and found that a shocking amount use underrated parts (especially capacitors.

For my part, the oldest LED retrofit bulb is hanging in our living room back home. It's IKEA, probably 4 years old, and no issues what so ever.

 

[foraloysius]

I have a lot of those Ikea bulbs too. Really like them, including the warm colour in contrary to the first ones. So far no problems with them.

 

[d-jones]

I've been reluctant to switch to LED bulbs or compact fluorescents for years simply because I found them hideous to look at. All of them looked as though they'd been severely beaten with an ugly stick. But now that LED Filament bulbs are available I've been gradually swapping them in all over my house. To the casual observer they look just like ordinary light bulbs, they come in a wide variety of styles, and the color of light they produce is warm like an ordinary incandescent.

 

[gusherb]

My oldest LED is a Philips 25 watt equivalent candelabra bulb. 5.5 years now showing no signs of weakness. Per my rough calculations just now, it has lasted approx. 32,120 hours. I believe it was rated for 25-30,000 hrs. It's a little dim but it was never a bright bulb to begin with, rated at 150 lumens. In the same lamp also sits an IKEA 25 watt equivalent candelabra rated for 250 lumens, about 2.5 - 3 years old. Also my only IKEA LED.

I'm really just not seeing the longevity claims with these replacement style lamps, which has been the fault of inferior electronics in every single failure so far. Cree has been great about honoring their warranty though, even sending me FIVE 3 packs of the TW series candelabra bulb when I only asked for 3 bulbs. So I'm set for life on the hanging pendants in the kitchen.

I think I said in the LED Christmas light thread that I hadn't had an Osram/Sylvania LED fail on me yet and then ironically three days later one failed. I made a claim with them and they're sending me a replacement no questions asked. Also, just shy of 3 years ago I ordered 30 GU10 50 watt equivalent bulbs for the track lighting at work and they all failed within a year. Lighting Ever was great about honoring the 3 year warranty. They all got replaced at least twice under warranty and this last time around they just gave me a refund. That's great service IMO.

I'm not sure what these companies long term goals are, making inferior LED lamps while offering long warranties, I would guess the warranty is to build up confidence but the issue is these lamps aren't lasting and people are pissed. And the companies are losing money on the people who remember they have a long warranty. The other people who forget they have a long warranty are feeling burned and just tossing these expensive lamps. I suppose at some point the companies will tighten down on their policies and make people provide proof of purchase and send back the original lamp, as most all of their written policies already state. That won't bode well for people with prematurely failed lamps though.

 

[gusherb]

David

I saw these frosted Philips bulbs at Homo Depot the other day. So far my favorite filament style LED, they're silent and completely indiscernible from incandescent unless you read the markings.

 

[firedome]

not sure if its true....

but Efficiency Vermont claims that Energy Star LED lamps are far superior in life-expectancy as compared to non ES bulbs. The past year we've been able to buy Sylvania Energy Star rated bulbs for 95 cents each, under their subsidy program we've put them in all sockets in both houses and stocked up well for the future:

https://www.efficiencyvermont.com/tips-tools/guides/how-to-choose-the-best-quality-led-bulb

 

[gusherb]

When one of the Cree 60 watt equivalent Classic bulbs in one of the sconces at work failed I replaced it with a NIB one I had bought when they were clearing them out for the 4Flow. As you can see there is quite a discernible difference in light output from the brand new one on the left and the 3 year old one on the right with about 12,000 hours on it. Methinks if the one on the right did last it's rating of 25,000 hours it would be quite dim as to be nearly unusable by then.

 

[ken]

Very interesting. I was not aware the output of led bulbs diminished with use.

 

[cfz2882]

LED reliability

I have had very good reliability with the ~30 LED lamps I have in use at home and at the shop:a couple I have had on constant since 2010,others are on grinders,machine tools and other high vibration areas and not one failure in many years One design I did have trouble with was a Chinese made LOA brand par lamp that used t 1 3/4 diodes,(56 IIRC ),in two series strings with no current control-lamps would last about a week,then a diode would short and cause cascade failure of other diodes in the string.LEDs can dim with use-a few different modes could be in play:aging of phosphor in leds that use phosphor(white LEDs),polymer covering over chip yellowing or becoming opaque,chip aging with use-putting out less light.That last cause seems evident with my GE clock radio(green LED)in constant use since 1980:when new,clock would light up a dark room on full brightness and transformer area of clock would get warm-after about a decade of use,clock would no longer light a dark room and transformer area would not get warm-indicating less current pulled by LEDS.Today,clock display seems about 40% as bright as new.
The oldest LEDs I have in my collection are from 1971,a little red blob with a lead going in each end.First initial use of LEDs for electronic indicators seems to have started ~1968 to become common in T 1 3/4 style by ~1975.

 

[sudsmaster]

With LED bulbs, be careful putting them into small enclosures. They may overheat in there and that will shorten their life.

I started out with CREE brand LED bulbs because their relatively high CRI, but was not real thrilled with their look, efficiency, or longevity. I have since switched mostly to Feit brand bulbs from Costco. Their Tru-Color bulbs have pretty good CRI (92+) and seem to last quite awhile, even in enclosed glass fixtures. My only complaint might be the FM radio interference, but I think most LED bulbs do that. The Feit bulbs are quite energy efficient, a number that seems to get better every year, with their wattage approaching just 10% of equivalent incandescent bulbs. The older ones had heavy aluminum fins near the base. The newer ones apparently are able to dispense with that heat dispersing method, and have a smooth base. I haven't had on fail yet, but when it does I may try to saw it apart to check out the electronics.

My only problem now is what to do with the pile of CFL's, many NIB, that I have accumulated before switching over to LED's.

The new filament LED's are nice. I have a few of them at the 2300 K very warm color level installed as mood lighting around the place. 40 watt equiv at 4.5 watt consumption.

 

[gusherb]

The oldest LED equipped devices I have are a few Western Electric Trimline telephones from the late 70s & early 80s. They light the dial pads nicely to this day, but those are not in a constant on application so no surprise there.

I have a pile of CFL's as well, mostly stocked up on them just because when they were selling for $.97 a box. I've been using them in the outside lights but may go LED in those when the CFL's die since I have a stock pile of LED's as well now. I'll probably just pack the CFL's away and keep them as a museum piece later on about what energy efficient lighting was like around the turn of the century.

 

[kb0nes]

For about 10 years now I have had a basically 100% LED lit home, no incandescent or compact florescents. At the point that the 60w replacement lamps hit ~$20/ea I changed over. The only incandescent lamp in the home is in the self cleaning oven (for obvious reasons).

I have yet to have a single lamp fail in my home. Probably about 30 or so lamps total, mostly Cree or Phillips, I tried to avoid buying any off brands.

I did have one first generation Cree 60w eq A19 lamp fail at work, it started to flicker but never died. One friend of mine has slightly more checkered luck with with lamps he has had in recessed ceiling cans, I think he had about 3 or 4 fail in a couple years.

Even if I had more failures I'd still be perfectly happy. The lamps are basically paying for themselves in energy cost savings in about a year. I sure haven't minded not having to replace a lamp in years too. Now if I could stop having to replace the smoke detector batteries every 2 years or so lol

 

[vacerator]

With some types,

the driver is replaceable at a minimal cost of about $10 to $15, as opposed to a new fixture entirely. They plug in like a typical pcb board connection.

 

[sudsmaster]

A few years ago I worked for a company that made manufacturing equipment for CREE. Stuff like vacuum chambers. Didn't give me any insight into how Cree does stuff, though.

The FEITS have been pretty good here. Esp the newer finless "Tru Color" designs.

I remember getting some LED night lights a while back. They were not very effiicient in terms of watts per lumen. Probably because they had very simple circuits - mainly a bridge rectifier with four or five resisters and probably a diode or two. No transistors like in more efficient power circuits. They didn't give out much light and most of them have been retired to the refuse bin.

What I'd really like to have is a mogul base 100-200-300 watt equiv. LED bulb. So far, nothing out there like that.

 

[ken]

Funny you mention led night lights. I just bought a twin pack two days ago and I concur about them not being very bright. But they are sufficient for what I need. They were the only option that were auto on/off. The brighter option was equipped with manual on/off switch.

 

[gusherb]

I bought an LED night light bulb many years back and used it for a long time. Still have it, just not in service currently. Earlier this year I saw a 3 pack of LED night light bulbs at wal mart and got them, only to find they flicker just like those Christmas lights I despise.

Saw some 40 watt filament style candelabras at Homo Depot today for $2.98 a 3 pack after local utility subsidy and picked them up, unfortunately they don't really work with my dimmer despite saying dimmable. Interestingly they dimmed very well with incandescents on the dimmer but put just those LED's in and there were only two levels of brightness. Those are going back and I'm trying the Cree candelight dimming bulbs instead for $4.97 for a two pack. Those aren't aesthetically pleasing like these filament style bulbs though.

 

[cfz2882]

trimline phone lamp

I have some of those phones too-unique LED in those,probably made by Western Electric themselves-just like the rest of the parts in WE phones.Custom twin chip green LED to run on AC.I have found some WalMart "great value"LEDs I like:100w equiv.,they are ~$12 two pak,look cool and do a good lighting job-have installed 5 of these at the shop so far-reliability remains to be seen...