Help! My LED build isn't working right

[robpardee]

I built a 24 LED retrofit for my aquapod a couple years ago. I had it in storage the last year as the tank was not setup but it has been setup again. The light worked great until today, the blue lights started to flicker then went off. I took the hood down and started checking out the wiring and all but I cannot figure out what's wrong with the blue LEDs. There are 12 LEDs of each white and blue alternating on a heatsink. Each white and blue is separately wired into a power source (a meanwell ELN-60-48D). I also have it setup to dim separately with a separate 12V power supply. I've checked what I can to see if there is any difference between the white and blue and so far unless the dimmer is all the way down the voltage across the 12 LEDs is 48V the whole time but they barely light up as you can see in the picture. The white LEDs voltage varies as I dim them. I checked the voltage of the Rheostat and it is properly going up and down for both colors.

What is the likely cause? Is the Meanwell dead?

 

[asdfghp]

Swap the power supplies to see if you have a problematic PS.
AND/OR
These LEDs are hooked up in series ..... When one goes out, it usually means the whole "string" goes out with it. Check each individual LED.
AND/OR
Check various points of the circuit to make sure nothing is shorted to the heatsink.

 

[robpardee]

I just started checking each LED and one when I crossed the positive and negative with the multimeter they all lit up. I am going to replace this LED but this is the second that has gone out. What could cause this but still let it light up dimly?

 

[asdfghp]

Make sure you are drivng the LEDs with the proper voltage and current.

Heat is the devil to an LED. Make sure the LEDs are properly attached to the heat sink and be sure to use a thermal compound.

Some LEDs get so hot that the oil of a fingerprint is sufficient to create a "hot spot" and cause it to fail. Clean the lens of each LED with a clean cloth and alcohol after handling them.

 

[robpardee]

I've never thought about using alcohol and a cloth to clean them up but that's a good idea. My heatsink had only been warm to touch. Never so hot I couldn't leave my fingers on it, it's well ventilated by a couple fans. I used a thermal sticker to attach them to the heatsink but I'll have to check them and make sure they are all tight to the heatsink. Thanks for the input!

 

[mpderksen]

Help! My LED build isn't working right

Another test, assuming you have dimmable drivers. Disconnect the 1-10V side and plug in 2 AA batteries. That's 3V and they will then be at 30%. I ran mine a few weeks that way while I waited for my controller. You can also check the current coming off the drivers. Your LEDs will have different voltages. I think my whites are 1200, but my blues I had to open the driver and dial back to 700 mA using a multimeter. If you never did this, perhaps they got cooked?

Edit: just looked at your pics, and yes, you have dimmable, so the tests above will work. I've built 3 fixture this way.

 

[oreo57]

I built a 24 LED retrofit for my aquapod a couple years ago. I had it in storage the last year as the tank was not setup but it has been setup again. The light worked great until today, the blue lights started to flicker then went off. I took the hood down and started checking out the wiring and all but I cannot figure out what's wrong with the blue LEDs. There are 12 LEDs of each white and blue alternating on a heatsink. Each white and blue is separately wired into a power source (a meanwell ELN-60-48D). I also have it setup to dim separately with a separate 12V power supply. I've checked what I can to see if there is any difference between the white and blue and so far unless the dimmer is all the way down the voltage across the 12 LEDs is 48V the whole time but they barely light up as you can see in the picture. The white LEDs voltage varies as I dim them. I checked the voltage of the Rheostat and it is properly going up and down for both colors.

What is the likely cause? Is the Meanwell dead?

Meanwell dimming circuit does NOT like voltages over 10V.
Good chance the driver is damaged..

Keep in mind that the Meanwell ELN-60-48D doesn't do well when you exceed 10.6v

somewhere here there is an "official" Meanwell response confirming this..Not sure if it here but a ton "o" stuff:
http://www.reefcentral.com/forums/showthread.php?t=1793374&page=6

 

[robpardee]

Your right, I just double checked the output of the plug for dimming and it is 10V, my mistake. In fact when I was checking the rheostat the voltage never got above 9.8V.

 

[oreo57]

Your right, I just double checked the output of the plug for dimming and it is 10V, my mistake. In fact when I was checking the rheostat the voltage never got above 9.8V.

good, but it still sounds like a dead driver..
Swapping the 2 will prove it. If you want to bypass the pot/ps just wire a 9V battery in it's place..

 

[robpardee]

Replacing the one led has so far fixed it. If it happens again I'll switch the drivers and see if that makes a difference