Need help with diy cob panel please! They stopped working :(


Hello fellow gardeners

Been gardening for some years under hps but a few months ago decided to finally gather some €'s and switch to led :) thumbs up!

Well, i searched a lot before, and now i have a 200w diy cob panel, made at home with only good materials.

The cob's are four Vero 29 SE Array, BXRC-35E10K0-D-73, running at 1400mA with an HLG-185H C1400A.

Each have it's own heatsink, 86x60mm, to where they are connected with screws and MX-4 underneath, above those are four fans, 12V 1,44w (that i'm going to switch for lower power ones) running with a small PS of 12V 3A (the one i could get).

Everything is well connected and tight with an aluminium frame that I made.

Well things were great till a few days. I tested the cobs with the heatsinks and fans before making the aluminium frame and everything was working fine, but now, after so much work and so carefully do everything well it doesn't light up... (but the fans do... why not the other way?? @#$%^&) "sorry."

The parts were kept in original package while I assembled the frame so there was no accident with babies, dogs or cats.

I checked the input, output, all ok, 230V - 143V.
I checked all led connections and polarities , ok too.

What could possibly went wrong?
What should I assume?
Please help me, I can't find a web answer to this and don't know if the guys from support can help me because this is all brand new and was working...

Cheers for listening


Thank you very much for your help!

I thought so...

Tell me, can I do that job without the need of dimming the driver? In support they said yes because the driver ajusts the voltage automatically, is this right?


Cheers m8!

Already opened each cob case and connections are fine... polarities too.
Gonna try that method.
But what should be the problem..?
Hope every chip is ok... but if that was the case it should work... :(


Well-Known Member
Is the little bd, right of the driver, for the fans

I'd start with eliminating the fans

If it worked prior to building the frame.....welllllll..a connection must have come loose cuz it wouldn't be a grounding issue

Check every wagu and every connection

Eliminate some, test, then go from there

Rocket Soul

Well-Known Member
You are running your driver right around the edge of how much voltage it can do. Its max V is 143, if you add up your voltage for 1400mA you get 144.8V. Try dimming it down all the way down and turn it on again. Or disconnect 1 cob and see if it works. If no joy with 3 cobs id say you might have a broken driver.


Can u see the black wires in this pic?
One comes direct from driver + and go direct from cob to cob (- to +) till goes to driver -


Ok got ya, I have the + and - from driver's output connected with those screw type connectors but everything else is direct.

Only the fan circuit has wagos but i'm going to shut it off in the input to have only the cobs working for the tests.

I'm going to try taking off from the series one cob at a time and see how it goes from there.

Thank you very much for your attention and help
I'll post feedback after job done ;)


Well-Known Member
On my SE arrays, I had an issue with a single push connector on one of the cobs.
Although everything looked like it was secure, it was making intermittent contact.
I only found it after removing the wires from the cobs.
This was after a couple of seasons of use.


Well guys, after two hours of checking and reconnecting, the problem was solved! Hurray!

After rechecking every cob I saw there was no problem with any connection, every wire tight well inside the push connectors, all polarities were good, so i tried removing one from the series. Same result. Removed another. No light...

Than I ripped apart all the wire holding zipties pissed off thinking my cobs are ruined :fire: and after everything is loose again noticed that the driver output had the + going for the - of the first cob.

I know, than i shot my head.:wall:

Sorry guys this things happen you know... :bigjoint:
Dimmed to minimum. Tj = 52C° with fans on ;)
Room temp: 25C°
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Dimmed to maximum. Fans off - Tj = 75C° after 1min working.
Room temp 25C°
Is this ok?
If the fans some how stop will it make my cobs blow? :confused:
Maybe I should throw another thread for this?