Please help me to stop blowing my LED's

I

iamthevibe

Member
hey all.

I really need help to figure out what to do and I am hoping someone can point me in the right direction.

After watching growmau5's video where he made a veg light using 20 cxa2530 cobs and 2 hlg 185-c500's I decided to copy his idea, but just half it as my space isn't even close to as large.

I decided to get the cxb2530's but otherwise got the exact same components.

First I tried to just power one LED to see if everything was working and how difficult that would be. I in turn burnt out my first LED.

After a lot more research and seeking advice from growmau5 I realised I needed at least 5 cobs in series for this driver. Totally fine. I tried to use the cob holders I had purchased, but they very finiky and I was struggling to get them to work.

Instead I soldered each cob and attached them to their own heatsinks. Everything seemed fine. I was able to turn everything on and was happy. I had a friend come look at the unit for me and he warned me that some of the exposed cables were touching the heatsink and I would need to get some heat shrink and make it safer.

Once I had removed all the cobs I decided I would try use the cob holders once more, with no luck. I tried to use a volt-meter to see where the issue lied. I'm not sure if I did something stupid in this phase. A couple times after unplugging the driver and trying to fiddle with the cables the lights would ignite for a split second.

The next day I went back to soldering everything in series. When I turned them on I noticed none of them were lighting properly, I could see each of those little blocks in the LED itself (not really sure how better to explain that). On two of the LED's after they looked like this: IMG_3920.JPG IMG_3921.JPG

So now I have 3 LED's that look like that. I am terrified to plug in my other LED's. How do I test if they are blown or not? Is it safe to use an LED that has been damaged? I am very disappointed and would love any help.
 
SupraSPL

SupraSPL

Well-Known Member
One major threat to a COB is intermittent power from a high voltage constant current driver because it can kill a COB instantly (over voltage). Because of this all wires have to be 100% secure during testing, especially if there is a single COB on a high voltage driver. Since your HLG-185H-C500 is capable of up to 400V, any crackliness/shorting/less than perfect soldering joints or connectors could easily result in a dead COB or even multiple COBs. The drivers pushes as hard as it has to to get current to flow, so when it suddenly loses connection it tries to push as hard as it can (400V) and when the connection suddenly returns the COBs can experience over voltage before the driver can reduce the voltage.

Another danger is when the COB loses contact with the heatsink, or large air bubbles in the thermal paste. The COB can take a lot of heat but there is a huge amount of power dissipating in a small thermal mass without the heatsink in contact.

One more possibility, any pressure that was applied to the LES can damage or break there very delicate gold traces that run between the dies.

Hopefully that helps you track down the problem good luck!
 
Stephenj37826

Stephenj37826

Well-Known Member
SupraSPL said:
One major threat to a COB is intermittent power from a high voltage constant current driver because it can kill a COB instantly (over voltage). Because of this all wires have to be 100% secure during testing, especially if there is a single COB on a high voltage driver. Since your HLG-185H-C500 is capable of up to 400V, any crackliness/shorting/less than perfect soldering joints or connectors could easily result in a dead COB or even multiple COBs. The drivers pushes as hard as it has to to get current to flow, so when it suddenly loses connection it tries to push as hard as it can (400V) and when the connection suddenly returns the COBs can experience over voltage before the driver can reduce the voltage.

Another danger is when the COB loses contact with the heatsink, or large air bubbles in the thermal paste. The COB can take a lot of heat but there is a huge amount of power dissipating in a small thermal mass without the heatsink in contact.

One more possibility, any pressure that was applied to the LES can damage or break there very delicate gold traces that run between the dies.

Hopefully that helps you track down the problem good luck!
Click to expand...

Use holders bro. No need in risking these high dollar cobs to save a couple bucks man. Im decent at soldering but ill stick to soldering pots and wires together. I dont have the nerve to solder to these cobs. dont get me wrong Im sure id do fine but why when you can avoid it.


I see you are using holders. what brand?
 
Last edited:
I

iamthevibe

Member
@SupraSPL
Ok. Great. So from where I am now, how do I test which LED's are still fine? Is there a driver I can get that I can use to test my LED's before all 10 are in series? Is it safe to use LED's that have been damaged?

@Stephenj37826
The LED cob holders I got where these: http://www.mouser.co.za/ProductDetail/Molex/180555-0002/?qs=sGAEpiMZZMvuxEGc54HwjXzM7szC%2b9CKWF5bCF5c1KkZbpf5pvutfA==

I really had major difficulty with them. Are there other ones that would be better?

I have now spent my budget, what cobs could I get to replace the cxb2530's that would be the cheapest? Even if its just for a couple of months.
 
G

GrowUrOwnDank

Well-Known Member
iamthevibe said:
hey all.

I really need help to figure out what to do and I am hoping someone can point me in the right direction.

After watching growmau5's video where he made a veg light using 20 cxa2530 cobs and 2 hlg 185-c500's I decided to copy his idea, but just half it as my space isn't even close to as large.

I decided to get the cxb2530's but otherwise got the exact same components.

First I tried to just power one LED to see if everything was working and how difficult that would be. I in turn burnt out my first LED.

After a lot more research and seeking advice from growmau5 I realised I needed at least 5 cobs in series for this driver. Totally fine. I tried to use the cob holders I had purchased, but they very finiky and I was struggling to get them to work.

Instead I soldered each cob and attached them to their own heatsinks. Everything seemed fine. I was able to turn everything on and was happy. I had a friend come look at the unit for me and he warned me that some of the exposed cables were touching the heatsink and I would need to get some heat shrink and make it safer.

Once I had removed all the cobs I decided I would try use the cob holders once more, with no luck. I tried to use a volt-meter to see where the issue lied. I'm not sure if I did something stupid in this phase. A couple times after unplugging the driver and trying to fiddle with the cables the lights would ignite for a split second.

The next day I went back to soldering everything in series. When I turned them on I noticed none of them were lighting properly, I could see each of those little blocks in the LED itself (not really sure how better to explain that). On two of the LED's after they looked like this: View attachment 3576532 View attachment 3576533

So now I have 3 LED's that look like that. I am terrified to plug in my other LED's. How do I test if they are blown or not? Is it safe to use an LED that has been damaged? I am very disappointed and would love any help.
Click to expand...
When I was in electrical technology class at college one genius decided to to use his little electrical science kit and power a single low wattage cheap red LED straight to a 9 volt battery. That mother fucker blew straight the fuck up! I mean POW like a firecracker and probably the top is still in the ceiling. Thankfully the genius didn't lose an eyeball.

Son. Don't ya know engineers are really smart? They have to go through school and learn stuff. Good luck with that. I would suggest in the future let the people with real skills design and build your stuff. You could lose an eyeball.
 
Banana444

Banana444

Well-Known Member
What do you mean by cheapest? In terms of the light output and power savings the cxb3590s are the "cheapest", btw i hate that word. For a temporary fix, get a 400w hps or mh setup. Dont take this the wrong way but it looks like you could use some practice assembling electronics. The holders are great for keeping things simple,take the time to figure them out and use them. There is a good amount of info and videos of assembling these things. Also at the least wash your hands before handling cobs, i wear tight fiting nitrile gloves to avoid getting oils from my hands on the LES, which is imu fairly delicate and easily damaged even by static electricity.
 
Rahz

Rahz

Well-Known Member
It looks like you originally had a single cob fail using a holder. You mention needing 5 cobs in series but if the driver is constant current (HLG_185H-C500) then one cob should light up without issue.

I'm wondering if you've had failures from both drivers or if all the cobs are failing on one of the two?

I'm also wondering if the first failure happened the same way as the others? With the same discoloration?

iamthevibe said:
hey all.

I really need help to figure out what to do and I am hoping someone can point me in the right direction.

After watching growmau5's video where he made a veg light using 20 cxa2530 cobs and 2 hlg 185-c500's I decided to copy his idea, but just half it as my space isn't even close to as large.

I decided to get the cxb2530's but otherwise got the exact same components.

First I tried to just power one LED to see if everything was working and how difficult that would be. I in turn burnt out my first LED.

After a lot more research and seeking advice from growmau5 I realised I needed at least 5 cobs in series for this driver. Totally fine. I tried to use the cob holders I had purchased, but they very finiky and I was struggling to get them to work.

Instead I soldered each cob and attached them to their own heatsinks. Everything seemed fine. I was able to turn everything on and was happy. I had a friend come look at the unit for me and he warned me that some of the exposed cables were touching the heatsink and I would need to get some heat shrink and make it safer.

Once I had removed all the cobs I decided I would try use the cob holders once more, with no luck. I tried to use a volt-meter to see where the issue lied. I'm not sure if I did something stupid in this phase. A couple times after unplugging the driver and trying to fiddle with the cables the lights would ignite for a split second.

The next day I went back to soldering everything in series. When I turned them on I noticed none of them were lighting properly, I could see each of those little blocks in the LED itself (not really sure how better to explain that). On two of the LED's after they looked like this: View attachment 3576532 View attachment 3576533

So now I have 3 LED's that look like that. I am terrified to plug in my other LED's. How do I test if they are blown or not? Is it safe to use an LED that has been damaged? I am very disappointed and would love any help.
Click to expand...
 
Rahz

Rahz

Well-Known Member
It's been tinned by the solder so that's not unusual, plus it wasn't like that when he first burnt a cob using the holder.

My experience with CXBs is that they don't take solder easily. I wipe them down with acetone first and the solder goes on fine with some flux or flux core solder. This is in contrast to Veros which have silver-ish solder pads and solder glides on easily.
 
littlejacob

littlejacob

Well-Known Member
Bonjour
It look like some dies are fried!
What kind of TIM did you use...and what hs?
If you look for cheap chips go for Vero10 or 13...it will be perfect with this driver...try cutter.au with cuttandroll code!
CU
 
Mellodrama

Mellodrama

Well-Known Member
Clearly the OP needs a safe, reliable, simple method to test his remaining COB's individually. I'm not sure what to suggest, other than buying a small driver that's only capable of sparking one COB at a time. Is there a safe test method using a couple of batteries?

I didn't think you could strap just one COB to a higher voltage driver intended to power several COB's and flip the switch, but Supra didn't seem to be alarmed so I'm a bit confused.

The Ideal Chip-Lok holders seem to be more popular on RIU. I don't know if they're any better than the Molex. I only have experience with Ideal. Like Stephen in Post #3, I'm not thrilled about soldering that close to the diodes when there are alternatives.
 
littlejacob

littlejacob

Well-Known Member
Bonjour
His holder look like Vero holders...is it harder to put a cob in those than in ideal holders?
You just slide the cob and lock it...how
did you proceed with yours?
CU
 
mc130p

mc130p

Well-Known Member
Rahz said:
It looks like you originally had a single cob fail using a holder. You mention needing 5 cobs in series but if the driver is constant current (HLG_185H-C500) then one cob should light up without issue.

I'm wondering if you've had failures from both drivers or if all the cobs are failing on one of the two?

I'm also wondering if the first failure happened the same way as the others? With the same discoloration?
Click to expand...
I think that the 200V minimum output would fry that single cob, unless it has over-current protection. Didn't feel like reading that much...lol

oh, the datasheet says there is SC protection, but idk how much current will flow before it kicks in.

Be safe!
 
Mellodrama

Mellodrama

Well-Known Member
littlejacob -
With the "Search" function you can find some of my older posts, where I went on & on to the point of annoying people about how to use the Ideals. I haven't kept up on what Ideal offers, so I don't know if they have holders for the latest COB's yet. The Ideal holders I used (CXA3070 holders) were a bit fussy. It definitely takes some practice and some discipline too. It might even help to be a little bit OCD ;)

I was hoping someone would come along with a homebrew battery-based tester for the OP. If there is no such thing, then I still think his next step is to buy a small driver with only enough power to fire one COB. Figure out what his damages are right now before going any further.

Next question: how does one test these high-power drivers? Do you need fancy test gear to verify their output? Or can a good multimeter be used somehow? I don't know but at this point I wouldn't be assuming that anything - COBs or drivers - were working as they should.
 
nogod_

nogod_

Well-Known Member
Hello. First off, that driver can kill you.

Number one rule of thumb....do not rush when you are building these. Find an afternoon when you have absolutely nothing to do for 8 hours straight and start then.

If you used the holder you linked it is for the wrong size. That holder is for the cxa13xx series. Does the cob fit in the square on the back side? (Sounds stupid but in the 2nd pic it looks way too big)

You can solder and kapton tape these but practice soldering on something else. A lot.

Make sure you're hooked up to the right pads.

Use an extra thin layer of TIM. I suck at applying it so I made a stencil out of blank sticker paper from office depot and used a putty knife.

Clean everything like you're about to eat off of it.

How many cobs do you have left?



iamthevibe said:
@SupraSPL
Ok. Great. So from where I am now, how do I test which LED's are still fine? Is there a driver I can get that I can use to test my LED's before all 10 are in series? Is it safe to use LED's that have been damaged?

@Stephenj37826
The LED cob holders I got where these: http://www.mouser.co.za/ProductDetail/Molex/180555-0002/?qs=sGAEpiMZZMvuxEGc54HwjXzM7szC%2b9CKWF5bCF5c1KkZbpf5pvutfA==

I really had major difficulty with them. Are there other ones that would be better?

I have now spent my budget, what cobs could I get to replace the cxb2530's that would be the cheapest? Even if its just for a couple of months.
Click to expand...
 
You must log in or register to reply here.
Top