Steve's LED Smoking

[thadius65]

I was setting up my Bluefish controller and after all was good, I ran some of the demos. I saw a puff of smoke on one of the lights. It still works, but obviously not as bright. What causes this and can just one be replaced? Can I still us it like this?

Thanks!

 

[oreo54]

I was setting up my Bluefish controller and after all was good, I ran some of the demos. I saw a puff of smoke on one of the lights. It still works, but obviously not as bright. What causes this and can just one be replaced? Can I still us it like this?

Thanks!

Well that's sad. Is that a new strip?
Not sure what caused it. Maybe oil/ dirt on the lens.
I' d be curious if the diode works underneath the carnage.

As to fixing more than likely though not exactly easy.
Removing the diode and replacing is figgety work.

Talk w Steves.
Possibly you are driving it too hard?

Shorted?

Who knows.

Unless you exceeded the diodes mA rating I'd consider it a manf. defect btw

 

[thadius65]

Well that's sad. Is that a new strip?
Not sure what caused it. Maybe oil/ dirt on the lens.
I' d be curious if the diode works underneath the carnage.

As to fixing more than likely though not exactly easy.
Removing the diode and replacing is figgety work.

Talk w Steves.
Possibly you are driving it too hard?

Shorted?

Who knows.

Unless you exceeded the diodes mA rating I'd consider it a manf. defect btw

No, it is not new. I bought it used. All was working and the it just started smoking. It was only at like 40% when it did it. I have tried emailing Steve's as well as leaving voicemails over last 1.5 weeks. I get nothing.

 

[oreo54]

No, it is not new. I bought it used. All was working and the it just started smoking. It was only at like 40% when it did it. I have tried emailing Steve's as well as leaving voicemails over last 1.5 weeks. I get nothing.

Is the one strip w/ the bad diode all "off"?
Soo if you have a digital vom I'd test the diodes. On ohms or diodes.
Note the surface of the Rebel is conformal coated and the gold traces really easy to damage so use the solder points.
See image
IF the diode actually functions or registers OK (will light dim on Ohms but may be hard to see currently)
then just CAREFULLY cut the silicone dome off (l/r not up/down in the pic.) avoiding the little black square which I believe is a static suppressor.

If the driver is splitting the current between 2 parallel strips and one is out you have an issue that all the current is now on the remaining strip.
Need more info.

Removing a bad diode requires either hot air , hot plate or sometimes people who can work magic w/ a soldering iron.

From a hacking standpoint at this point I'd just jumper between the dead diode contact points and see what happens.

YMMV and consider this just an FYI..

From your other post I see that it looks like each strip has its own driver correct?

Blacking domes with high power blue/violet/uv diodes is not uncommon.
The high flux high energy photons "smoke" some organic residues/contaminants in the silicone.

 

[thadius65]

Is the one strip w/ the bad diode all "off"?
Soo if you have a digital vom I'd test the diodes. On ohms or diodes.
Note the surface of the Rebel is conformal coated and the gold traces really easy to damage so use the solder points.
See image
IF the diode actually functions or registers OK (will light dim on Ohms but may be hard to see currently)
then just CAREFULLY cut the silicone dome off (l/r not up/down in the pic.) avoiding the little black square which I believe is a static suppressor.

If the driver is splitting the current between 2 parallel strips and one is out you have an issue that all the current is now on the remaining strip.
Need more info.

Removing a bad diode requires either hot air , hot plate or sometimes people who can work magic w/ a soldering iron.

From a hacking standpoint at this point I'd just jumper between the dead diode contact points and see what happens.

YMMV and consider this just an FYI..

From your other post I see that it looks like each strip has its own driver correct?

Blacking domes with high power blue/violet/uv diodes is not uncommon.
The high flux high energy photons "smoke" some organic residues/contaminants in the silicone.

Thanks for all the info. The smoked diode works, it just lost some brightness compared to the others. so when the dome is cut off, how is it then protected?

 

[oreo54]

Thanks for all the info. The smoked diode works, it just lost some brightness compared to the others. so when the dome is cut off, how is it then protected?

Actually you just keep cutting off the bad part.
Unlike those bridelux egg shaped diodes where you can peel off the whole lens the si layer looks to be all inclusive in Rebel chip.
So just sheer off layers.

This is a last attempt before a real fix type thing. No guarantees.

As to orotection diodes are made of err ceramic, gold wires and "rock"

 

[thadius65]

Actually you just keep cutting off the bad part.
Unlike those bridelux egg shaped diodes where you can peel off the whole lens the si layer looks to be all inclusive in Rebel chip.
So just sheer off layers.

This is a last attempt before a real fix type thing. No guarantees.

As to orotection diodes are made of err ceramic, gold wires and "rock"

so I use an xacto knife to cut off the dome, then I just use it like that? no protection or coverage needed?

 

[Duncan62]

Well that's sad. Is that a new strip?
Not sure what caused it. Maybe oil/ dirt on the lens.
I' d be curious if the diode works underneath the carnage.

As to fixing more than likely though not exactly easy.
Removing the diode and replacing is figgety work.

Talk w Steves.
Possibly you are driving it too hard?

Shorted?

Who knows.

Unless you exceeded the diodes mA rating I'd consider it a manf. defect btw

I have several blues that look this way. The diode works on mine but the end is black. Mine are 5 year old bridgelux. leds.

 

[theatrus]

The best solution is always replace the LED. You can remove the lens, but expect corrosion to be a hostile environment.

The burning effect is when a piece of debris is stuck to the lens which causes a localized hot spot due to heating by light. It will burn away at the silicone lens.

 

[CayeCaulker]

Those chips are easy to solder on and off. You will probably need hot air. Not sure if you could pull it off with solder wick and a pencil.

but.. I solder for a living. It's all about the tools.

 

[oreo54]

so I use an xacto knife to cut off the dome, then I just use it like that? no protection or coverage needed?

If you look at the diagram there is 2 coats over the top of the chip.
I assume a conformal coat followed by the silicone lens coat.

Just don't cut too deep..Like cut 1/2 of the height of the dome, see if you removed most of the center browning..
You only need an aperature so to speak.

 

[CayeCaulker]

You guys are all making this too hard. It's designed to be soldered on. Hot air at about 280-320c held at a reasonable distance some flux and watch it flow. Then just pick it off and drop a new one on. The whole process would take about 20 seconds.

Find someone with a hot air station and just have them do it real quick. Without doing this right it's a mess. Most modern shops have them. Lots of cell repair places have hot air.

Can you source the chip?

If you ship the unit to me and supply the chip I will replace it for $20


Otherwise, just run it like it is. I am sure it has bypass diodes. It is most likely a COB LED diode that is operated at a constant current. So it probably smoked part of itself down and some of the diodes are still trying to work. I wouldn't touch it unless you were going to replace it. You are not going to get useful light out what is left.

 

[oreo54]

You guys are all making this too hard. It's designed to be soldered on. Hot air at about 280-320c held at a reasonable distance some flux and watch it flow. Then just pick it off and drop a new one on. The whole process would take about 20 seconds.

Find someone with a hot air station and just have them do it real quick. Without doing this right it's a mess. Most modern shops have them. Lots of cell repair places have hot air.

Can you source the chip?

If you ship the unit to me and supply the chip I will replace it for $20


Otherwise, just run it like it is. I am sure it has bypass diodes. It is most likely a COB LED diode that is operated at a constant current. So it probably smoked part of itself down and some of the diodes are still trying to work. I wouldn't touch it unless you were going to replace it.

Technically I agree w/ you but here is the catch..

Luxeon Rebel Color Emitters

www.ledsupply.com

$5.83 for the diode, $7 shipping $20 for you and what return shipping (sorry you didn't state..)
$33 plus dollars for one diode..
I believe he could buy a new board for that price.
well new board $45..Guessing at size atm

PARmax2 Extreme 14-up LED Array - Solderless

www.stevesleds.com

Or buy a "hotplate"
$15 plus solder and flux or a hot air station for $40 or so..

Vs just cutting the lens or jumpering around it if you screw it up....for free

 

[CayeCaulker]

Technically I agree w/ you but here is the catch..

Luxeon Rebel Color Emitters

www.ledsupply.com

$5.83 for the diode, $7 shipping $20 for you and what return shipping (sorry you didn't state..)
$33 plus dollars for one diode..
I believe he could buy a new board for that price.
well new board $45..Guessing at size atm

PARmax2 Extreme 14-up LED Array - Solderless

www.stevesleds.com

Or buy a "hotplate"
$15 plus solder and flux or a hot air station for $40 or so..

Vs just cutting the lens or jumpering around it if you screw it up....for fr

Well, I would just replace that board! Trying to get useful light out of smoked COB won't get you much of anything. They operate at constant current and what's left won't last long if it is lighting up. It will smoke itself down and disappear like a white dwarf star. The remaining chips on that IC will take too much current and give it up.

If the board only costs $45 just replace it. Or let the COB burn itself out and live without it.

I wish you were local you could just swing by the shop and it would only cost the chip. I wouldn't have to ship it back

 

[oreo54]

Well, I would just replace that board! Trying to get useful light out of smoked COB won't get you much of anything. They operate at constant current and what's left won't last long if it is lighting up. It will smoke itself down and disappear like a white dwarf star. The remaining chips on that IC will take too much current and give it up.

2 diodes or 15 diodes, current remains the same.
If not overheated too bad, lifespan isn't shortened. Damage is to a silicone or plastic lens not the chip itself..
you can melt or burn the gold wires or deform the crystal or add contaminants though..

Overall pretty tough stuff though..

Indium gallium nitride is the light-emitting layer in modern blue and green LEDs and often grown on a GaN buffer on a transparent substrate as, e.g. sapphire or silicon carbide. It has a high heat capacity and its sensitivity to ionizing radiation is low (like other group III nitrides), making it also a potentially suitable material for solar photovoltaic devices, specifically for arrays for satellites.

 

[monkeyCmonkeyDo]

If Steve's won't help you or get back to you...get ahold of rapid led. They will help you.
D

 

[CayeCaulker]

2 diodes or 15 diodes, current remains the same.
If not overheated too bad, lifespan isn't shortened. Damage is to a silicone or plastic lens not the chip itself..

Those chips are made up of dozens of small LED's packed into one dye. They call them COB arrays. I bet some of them shorted and melted down melting the lens in the process. The remainder of the LED's on that dye are all going to be damaged or are already damaged by the overdriving of constant current to the cluster. Whip out a pocket knife and pop that thing off and you will see the crater in the middle of the array.

When I speak of multiple diodes I am talking about all the diodes on that single chip. Not the rest on the board. That single chip could have 100 diodes on it. Diode break over voltage is like 3v. COB diodes run at much higher voltage and are regulated by constant current so they don't smoke down. that's because there is not one diode on the dye. they pack them in there to get a super bright LED. It's really dozens of small LEDS all packed together on a single chip.

 

[Karen00]

Technically I agree w/ you but here is the catch..

Luxeon Rebel Color Emitters

www.ledsupply.com

$5.83 for the diode, $7 shipping $20 for you and what return shipping (sorry you didn't state..)
$33 plus dollars for one diode..
I believe he could buy a new board for that price.
well new board $45..Guessing at size atm

PARmax2 Extreme 14-up LED Array - Solderless

www.stevesleds.com

Or buy a "hotplate"
$15 plus solder and flux or a hot air station for $40 or so..

Vs just cutting the lens or jumpering around it if you screw it up....for free

That hotplate is cool. I have to get myself one of those nifty tools!

 

[CayeCaulker]

This is a link to a quick hot air station.
These are super fast and easy to operate. Perfect for LED repairs. A little hard to justify for one job. I have used several hot air stations and this is my favorite.

Quick 861DW Hot Air Soldering Rework Station w/ Three Nozzles

If you've ever made a mistake when surface-mount soldering, you'll know how much of a pain it can be to fix it without the right tools. It can add critical time to a project and can ...

www.adafruit.com

 

[oreo54]

. A little hard to justify for one job.

Understatement of the day....