The "magic Smoke" LED light

[innkeeper]

Imagine my surprise when the spotlight in my kids playroom released the magic smoke.
and yes, it has that classic magic smoke smell
home depot ecosmart ECS BR30 W27 FL 120

[Don Hills]

Why is it still in one piece?

[mengfei]

yikes! smoke detector worked?
it's a fully closed bulb & no vents at all?
all heat rises top part & will surely kill it in due time, i had a lot of those unbranded ones die on my.

But those philips or osram one's are still alive & kicking after a year or so & some are even embedded in the ceiling with enclosure though they are just 3~5w LED.

[Brumby]

It's sights like that which give me nightmares.....

With the old-fashioned incandescent, this sort of fire risk was just not an issue.  Yes, it did have its issues, but nothing quite like this.  Same for CFLs.

[Cyberdragon]

Switching supply or cheap Chinese crappy cap dropper?

[FlashedBIOS]

Similar thing happened to me with a CFL.  I'm just waiting for one of these things to start a fire.

[MarkF]

I've had those fluorescent bulbs get really hot after a time.

[Sal Ammoniac]

Was the bulb in a fully recessed ceiling fixture? If so, was the bulb rated for that?

I'm begun to replace all of the incandescent flood lights in all of my house's ceiling fixtures (about 30 of them) with LED bulbs and am concerned about the failure modes of these bulbs. When incandescent bulbs fail, they just pop their filament and that's it--no melting of the bulb housing. LEDs tend to fail more spectacularly and I'm not sure that I trust them not to start a fire. 

[Red Squirrel]

Stuff is built down to a price so badly now days, but it's scary when it can potentially catch your house on fire. 

[Cyberdragon]

All that is needed to prevent this is a thermal fuse, even if it was a cap dropper. I wish electrical regulations would make it mandatory.

We bought some LEDs at the dollar store, I think they were like a dollar a box. You know what that means...

[innkeeper]

yikes! smoke detector worked?

relatively new house to me, and it turns out its the only room in the house that doesn't have a smoke detector. the rest of the house has wired smoke detectors with battery backup
Guess what i'm doing TODAY!

[innkeeper]

Switching supply or cheap Chinese crappy cap dropper?

i don't know...
I've not decided if i am going to tear it down, or contact the manufacturer on this.. but it is not like i care about getting a replacement under ther "5 year warranty" not like i want another one of these.

[Red Squirrel]

Switching supply or cheap Chinese crappy cap dropper?

i don't know...
I've not decided if i am going to tear it down, or contact the manufacturer on this.. but it is not like i care about getting a replacement under ther "5 year warranty" not like i want another one of these.

I would still raise a fuss with the manufacturer, send them pictures etc.  The more people do this the more they might realize that it's actually important to put some safety in their stuff so that it does not burn houses down.

[innkeeper]

Was the bulb in a fully recessed ceiling fixture? If so, was the bulb rated for that?

I'm begun to replace all of the incandescent flood lights in all of my house's ceiling fixtures (about 30 of them) with LED bulbs and am concerned about the failure modes of these bulbs. When incandescent bulbs fail, they just pop their filament and that's it--no melting of the bulb housing. LEDs tend to fail more spectacularly and I'm not sure that I trust them not to start a fire. 

The bulb was rated for a recessed fixture also rated indoor outdoor and dimable.  I actually had it in a ceiling fan, in one of the fluted glass fixtures to shine light in the area the kids play. (pictures attached below)

[innkeeper]

Doing a little research, seems these were sold circa 2011, so that is about right, its when i moved into the house so i might be past the 5 year warranty ... figures.

I have another in the house in a recessed spotlight...which i just pulled it out and its in great shape. however the light is not used often.. i'll do a disassembly of it and leave the burnt one alone.

these were $30 a bulb when they first came out. (found a thread here on them) http://www.candlepowerforums.com/vb/showthread.php?313789-Trying-out-the-new-Home-Depot-EcoSmart-LED-BR30-bulb
Good pics of the packaging there also.
 
the base is ceramic plastic, so what you see burnt and bubbling actually burst / burned though the ceramic plastic insulator at the base.
the white fins you see are metal heat sink fins, not plastic.

this was back when you paid a hefty premium for an led light, even the home depot brand.
chances are it is right at the 5 year mark - they advertised these to last 23 years.

[innkeeper]

TEARDOWN:
the burn spot corralates to the top side of the pcb,  right about where the UL Listed symbol is (ironic)
It is potted, i'll have to see if i can remove the potting material.
any suggestions?

[Towger]

Dremel

[Red Squirrel]

They should maybe start using fire retardant filler in these things.  If it does catch on fire it will just foam up and smother the fire.

[Electro Detective]

Magic Smoke should make its appearance on workbenches or sheds, not childrens rooms     

I still use old school incandescent globes and 12v downlights, with dimmers and ON-OFF switches to save money 

The light quality is SUPERIOR, easy on the eyes (and brain)

and no surprise ceiling mini barbeques   

[innkeeper]

TEAR DOWN PART II:

Dremel worked great. the potting material is kind of semi soft material and i can peel it off or break it in chunks.
not sure what kind of potting compound it is, but its not the solid epoxy type.

i peeled it back enough to get to the area that burnt on the other light.

Two shots of the tear down below. the area i have circled in red is the area were it burnt though on the bad one.
it appers very likely that either power transistor/mosfet type device got hot or the resistor above it and likely melted /burned the potting material and base area.
turns out the base area was not ceramic but plastic. The potting compound dosn't seem thermally conductive. It was likely there to keep it safe from the elements.

this should also answer the question on if the circuit it was a crappy cap dropper. it does seems like more of a proper circuit to drive the led.

[amyk]

I'll take a cap dropper (in a metal bodied lamp --- nothing to burn, just don't touch it when on...) over that ridiculous overengineered mess.

To make matters worse they potted it which likely increased temperatures to the point of failure.

[innkeeper]

i wonder if the potting material is flammable.

[rdl]

They should maybe start using fire retardant filler in these things.  If it does catch on fire it will just foam up and smother the fire.

Seeing how there's just the one spot that's burnt and the whole thing didn't go up in flame, it may be that it's a type of plastic that doesn't support combustion. Might be interesting to try and set fire to the plastic from the teardown sample.

[tom66]

Have seen an interesting failure mode on the SMPS power supplies at my old workplace.

During testing, we had one power supply burn up after being subject to excessive load for 48 hours (below the current limit trip at high-line voltage of 253V AC).   We couldn't figure out what happened but essentially the phenolic PCB and the MOSFET had got very very hot and burned up a huge section of the board. The MOSFET was shorted and the fuse was popped, but as far as we could tell, that wasn't the cause of the burning.

Later, we were able to replicate the failure.  Under high temperature the power supply controller could overheat and fail, but when it failed its output didn't go to zero.  It sat around 2-3V, which was provided by the Vcc charge circuit (the MOSFET was not switching at this point.)    So the MOSFET was being continuously biased with low gate voltage when it was supposed to be off, so it was conducting current continuously.  This wasn't enough current to blow the fuse, but was enough to make stuff very very hot and start burning stuff in the area.  Eventually, the MOSFET would succumb to short-circuit failure due to overheating, and pop the fuse, but that wouldn't happen for some time.  I wonder if something similar happened in your case.

[innkeeper]

Interesting. I did notice a "Buss" branded device in series with the input, and assumed it was a fuse, but the markings were not that clear, i'll look it up at some point but.. was surprised that it didn't blow that fuse.
what your describing would explain that for sure.