DIY Light started flickering

[Mortis]

Around 9 years ago I made my first proper LED light fixture. Specs are below

72 Bridgelux LEDs divided into 3 x 24 LEDs (2 x 12 LEDs in parallel)
Powered by 3 X Meanwell ELN 60-48-D Drivers
Dimming controlled by 3 x 10k OHM potentiometers and ONE DC 10V 1A Adaptor thats shared between all 3 drivers

Its has worked flawlessly over the last 9 years other than 2 pot failures that were easily fixed until today.

All 3 sets of LEDs were set to 50%

I tried to increase the brightness of the RGB channel today and after turning it to around 60% the entire set of 24 LEDs started flashing. Thank God I dont have epilepsy. Turning the dimmer either way had no effect on the flickering or intensity. The only point it was stable at was at its lowest where the LEDs are barely on and also not flickering.
It appears as though one LED in this set isnt working. This could be the cause of this set's failure

Now we come to the perplexing bit

The non functional set of LEDs was turned off and unplugged. To make up for the lower light levels while I fix it, I decided to turn up the intensity on the remaining 2 sets.
Set one went up and worked as normal

Now with Set two : Once I went past 60%, HALF of it i.e. one of the parallel strings with 12 LEDs started flickering the same way. However all the LEDs on this set are functional. After fiddling with the dimmer knob, it seems like it works completely normally until 30% intensity after which both parallel strings act weirdly in combinations of both flickering, one on one off, switching back and forth, etc,

This has left me perplexed on what could have gone wrong and how to rectify it.

Its not the potentiometers because when those pop they still work at 0% and 100% intensity
It could be the DC 10V adaptor that controls the dimming as the issue seems dimming related but then again one set of LEDs is working normally
The one blown LED could be the cause of the set its connected to not working but it doesnt explain why the other set is malfunctioning and that too in such varying and random patterns
One of the Meanwell drivers could have popped but I cant see how it would affect another driver that is only technically connected in parallel to the same DC 10V adaptor which only controls the dimming
All the visible connections seem fine and I dont think they would be affected because only turning the dimmer wouldnt shift any wiring connections. I could do a deep dive but its kinda dusty in there and my allergies are acting up plus Im fairly certain I wont find anything untoward.
The light has been run for long periods on higher intensities before and its actively cooled by fans in case anyone was wondering

Im looking for advice on what the most likely failure point is so that I can get it up and working again.

 

[Miniandy]

Get a voltmeter on the supply and then the 2 / 3 circuits. My guess would be the 10v adapter, but I always troubleshoot from source.

On a side note, I'd love to see how you've done it. Is there a build thread? I'm going to do my own this autumn.

 

[Mortis]

Get a voltmeter on the supply and then the 2 / 3 circuits. My guess would be the 10v adapter, but I always troubleshoot from source.

On a side note, I'd love to see how you've done it. Is there a build thread? I'm going to do my own this autumn.

Im quite rubbish with multimeters and basic electronics in general but I will give it a shot

No build thread unfortunately. Overall the light is great in terms or output and colour rendition without the horrible "blurple" look that a lot of fixtures have these days. I made a WRGB light before it was cool !! Haha. Its been extremely reliable over the past 9 years until now that is.
My packaging of the light is kind of blahblahblahblah but its functional. I had some variables I was unsure on how to deal with, difficulty procuring materials/tools, time, budget, etc so I managed with what I had. Could have been a lot better but it would have cost me more than the electronic components for an acrylic box not to mention the headache.
Its not a very complicated build and I could give you some guidance or a circuit diagram. The only issue is that the Meanwell drivers I used have been discontinued I believe. They are still available in some places but I dont know what the replacement for it is.
I basically just copied the components from a DIY kit someone was selling in the USA and bought them from China for 2/3rds the price

 

[oreo57]

Get a voltmeter on the supply and then the 2 / 3 circuits. My guess would be the 10v adapter, but I always troubleshoot from source.

On a side note, I'd love to see how you've done it. Is there a build thread? I'm going to do my own this autumn.

ON another side note and not to bash Mortis but to give you some food for thought.
1) Parallel strings and current division can be a bit risky (fry the array, not burn the house down risks) if some precautions aren't taken.
Think of it this way.. the above driver, using 2 parallel strings splits 1400mA between the 2 12 diode series strings.
That means each string "sees" 700mA ..well and good. Say one side opens.. then the remaining active string now gets 1400mA of current.
This could, at the least stress the diodes and weaken their output and at the worst cause thermal runaway destroying them.
Now put a 1A fuse on the end of each and it will blow if a side fails open.
And there are other things like the current isn't actually evenly split.
This can be mitigated with some added current balancing circuitry or an IC but that just complicates things.
2) 10V w/ pot dimming is a poor way to control an LED. It IS sort of industry standard but that is sort of the problem if you get my drift.
Generally won't evenly dim to zero and one usually uses a timer to cut line power to the driver. Another complication.
3) Other than simple manual control if one wants FULL control/programming 0-10v analog (1-10v analog) is either expensive (think Profilux or Apex or full Bluefish)
Using 5v PWM DC/DC drivers allows for relatively cheap control with DIY Aduino or a host of sub-$100 controllers.
And it will smoothly dim to 0.

BTW either using more drivers and an AC/DC power supply (like Meanwell LDDS) vs the "all in 1" AC/DC driver as in the above cost is generally a wash.
Now as to a replacement for their obsolete driver. There are some . Most now incorporate "3 way dimming"
pot only, 0-10v, or 10V PWM
There may be a catch though.
This one comes to mind but it would need longer strings.
HLG120H-C1400AB.
1400mA but min V(f) is 54V (108V tops)
So since voltage is additive say you have white diodes at 3-3.4V
19 minimum not 12 diodes in series, 2 parallel branches to split the 1400mA to 700 each.

Oh a direct replacement

Sosen SS-60L-42B, 60W LED Driver, 24-42V Output, 1450mA Output Current | 1000Bulbs.com

Power and protect your commercial fixtures with this LED driver from Sosen. Choose 1000Bulbs.com as your source for great deals on power supplies!

www.1000bulbs.com

1450mA 24-42V 3 way dimming so one can discard the 10v power supply.
Not water proof though.

That is all about a constant current type system.​

With Constant voltage all you need is a string of diodes, some resistors and there are even more cheap control systems like
every one that controls those RGB ribbons ect.
12 or 24v

To Mortis see you at planted tank..

 

[Mortis]

ON another side note and not to bash Mortis but to give you some food for thought.
1) Parallel strings and current division can be a bit risky (fry the array, not burn the house down risks) if some precautions aren't taken.
Think of it this way.. the above driver, using 2 parallel strings splits 1400mA between the 2 12 diode series strings.
That means each string "sees" 700mA ..well and good. Say one side opens.. then the remaining active string now gets 1400mA of current.
This could, at the least stress the diodes and weaken their output and at the worst cause thermal runaway destroying them.
Now put a 1A fuse on the end of each and it will blow if a side fails open.
And there are other things like the current isn't actually evenly split.
This can be mitigated with some added current balancing circuitry or an IC but that just complicates things.
2) 10V w/ pot dimming is a poor way to control an LED. It IS sort of industry standard but that is sort of the problem if you get my drift.
Generally won't evenly dim to zero and one usually uses a timer to cut line power to the driver. Another complication.
3) Other than simple manual control if one wants FULL control/programming 0-10v analog (1-10v analog) is either expensive (think Profilux or Apex or full Bluefish)
Using 5v PWM DC/DC drivers allows for relatively cheap control with DIY Aduino or a host of sub-$100 controllers.
And it will smoothly dim to 0.

BTW either using more drivers and an AC/DC power supply (like Meanwell LDDS) vs the "all in 1" AC/DC driver as in the above cost is generally a wash.
Now as to a replacement for their obsolete driver. There are some . Most now incorporate "3 way dimming"
pot only, 0-10v, or 10V PWM
There may be a catch though.
This one comes to mind but it would need longer strings.
HLG120H-C1400AB.
1400mA but min V(f) is 54V (108V tops)
So since voltage is additive say you have white diodes at 3-3.4V
19 minimum not 12 diodes in series, 2 parallel branches to split the 1400mA to 700 each.

Oh a direct replacement

Sosen SS-60L-42B, 60W LED Driver, 24-42V Output, 1450mA Output Current | 1000Bulbs.com

Power and protect your commercial fixtures with this LED driver from Sosen. Choose 1000Bulbs.com as your source for great deals on power supplies!

www.1000bulbs.com

1450mA 24-42V 3 way dimming so one can discard the 10v power supply.
Not water proof though.

That is all about a constant current type system.​

With Constant voltage all you need is a string of diodes, some resistors and there are even more cheap control systems like
every one that controls those RGB ribbons ect.
12 or 24v

To Mortis see you at planted tank..

So this setup has fuses on it but its concealed round the back so I cant remember if its for each string or for the full set of 24 and also what the fuse rating is lol.
Also these drivers output is 1300ma so it does limit each string to 650 ma
Yeah there was an option for PWM dimming if I had used the "P" version of the power supply but I was anyways stressing with even this "basic" light set up plus other factors and so I shose the simplest route and would do so again. Even with the knowledge I have now vs back then I prefer the KISS route generally and overspeccing stuff so that I never have to run anything electronic or mechanical at 100% capacity and having things easily repairable. Also sourcing stuff in India can be a pain sometimes. Its better now with the internet and online shops and it will DEFINITELY be available in a big city like Mumbai but finding out who has it, explaining what I want to someone who just stocks it but doesnt know what its for, explaining a project to someone who only knows how to do standard stuff, etc is a burden that I have to shoulder so in the end Im limited by my own skill and how much effort I want to put in.
Oh and dont even get me started on the "Local name" issue for stuff. If you dont know what an object is most commonly used for or the local name then even if the shop has millions of the thing on shelves right behind him, he will have zero clue what you are talking about. For example if you want a bulkhead for a drilled tank and you go to a hardware and plumbing shop and ask for a bulkhead the guy will be like wtf is that ? Then you show him a picture and he will go like " Oh you want a Syntex tank nipple ? What size and how many ? "
Its the unfortunate side effect of having a poorly educated average population and business people doing business without having a clue about what they are selling. Kind of like when you ask advanced aquarium questions to the average large chain petstore employee over there.
Something we have to unfortunately deal with when gaining knowledge on the internet from somewhere in English and with the technical details but then have to translate it and dumb it down to make use of locally.
See you on TPT !!

 

[Mortis]

UPDATE : Opened it up and cleaned it out. Replaced the cooling fans because might as well. Checked and redid all the main wire connections - they seemed fine anyways

Then I sat and tested each LED with the multimeter. Was quite painful to do 48 LEDs and remove and replace the lenses.

I found 2 LEDs (One on each set of 24) that did not light up with the multimeter, even though they did flash when powered normally. Tried various +ve and -ve point combos on both and they didnt light up while all the others did. Multimeter was set to Diode/Continuity(?) mode.

Replaced both of them and even with my poor soldering skills I tested and am sure I did it right. Turned the light back on and its still not working and is behaving the same as it was earlier.

So it seems like the LEDs were shot but not the reason for the flickering ? Ive ordered a replacement DC 10V power supply and will check if that helps. If not then Im lost and will have to take it to my electronics repair guy who is out of town for a month plus.

Anyways the DC 10V is gonna take a while to get here so I have ordered a Micmol Master light as a replacement. Im eager to test it out. The specs look good on paper and its bang for buck vs the Chihiros Pro series but there isnt a lot of info or reviews for Micmol Lights so hopefully I can put up a review as well for people that might be interested.