Did I overheat my QB? Broken QB

I have a question can anyone identify the problem on this QB? Its a kingbrite, i cut it up into three pieces too fit the tent, but upon inspecting it I noticed some weird markings next to some LED’s. Did they overheat? They have been running for almost a year.

Or did this maybe happen because of the way they are set-up? I forgot if these are connect in series, or not?

dendroaspis said:

I have a question can anyone identify the problem on this QB? Its a kingbrite, i cut it up into three pieces too fit the tent, but upon inspecting it I noticed some weird markings next to some LED’s. Did they overheat? They have been running for almost a year.
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Is the top photo current, and the middle photo when the kit was new?

What is the exact model of driver that is powering the light?

You mentioned kingbrite , there you go.

Barristan Whitebeard said:

Is the top photo current, and the middle photo when the kit was new?

What is the exact model of driver that is powering the light?

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they are both current.. one is dimmed the other is max power. At max power there is still a difference in intensity.
The driver is the meanwell hlg-320h-48b.

About my comment on in series. I can remember vaguely that either parrelel or series could cause trouble with leds. Is that maybe what happened here? Ita been a year since I dove into that material.

dendroaspis said:

they are both current.. one is dimmed the other is max power. At max power there is still a difference in intensity.
The driver is the meanwell hlg-320h-48b.

About my comment on in series. I can remember vaguely that either parrelel or series could cause trouble with leds. Is that maybe what happened here? Ita been a year since I dove into that material.

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It is a board, so it is prewired with a combination of series and parallel. Looks like something went wrong and now they are toast

Boatguy said:

It is a board, so it is prewired with a combination of series and parallel. Looks like something went wrong and now they are toast

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Thanks, as far as I can remember I followed the instructions. Well sucks to be me right now I guess.

So far kingbrite has always replaced broken parts, lets see how they handle this.

Budzbuddha said:

You mentioned kingbrite , there you go.

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I’ve orderderd a couple of times from them. In total me and my friend own 6qb’s and they work fine. Except this one. I’ve found their customer support to be superb aswell.

Boatguy said:

It is a board, so it is prewired with a combination of series and parallel. Looks like something went wrong and now they are toast

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I see, I think this board wired differently with this driver compared to my other QB’s. Maybe they are not suited for that. I’ll dive into that tomorrow.

dendroaspis said:

I see, I think this board wired differently with this driver compared to my other QB’s. Maybe they are not suited for that. I’ll dive into that tomorrow.

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There isnt a whole lot you can do to fix it. You should probably start shopping

Boatguy said:

There isnt a whole lot you can do to fix it. You should probably start shopping

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Jup, i guess so, though I’d like to understand fully why they are toast. So that if I’m to blaim, it wont happen again. I’m vegging for now. So i’ve got some time on my hands.

dendroaspis said:

they are both current.. one is dimmed the other is max power. At max power there is still a difference in intensity.
The driver is the meanwell hlg-320h-48b.

About my comment on in series. I can remember vaguely that either parrelel or series could cause trouble with leds. Is that maybe what happened here? Ita been a year since I dove into that material.

Click to expand...

That driver needs the boards wired in parallel. The + & - terminals of each board should be connected to the + &- output leads of the driver.

dendroaspis said:

Jup, i guess so, though I’d like to understand fully why they are toast. So that if I’m to blaim, it wont happen again. I’m vegging for now. So i’ve got some time on my hands.

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Call HLG and thank me later.

GBAUTO said:

That driver needs the boards wired in parallel. The + & - terminals of each board should be connected to the + &- output leads of the driver.

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Thanks, just woke up and was about dive into that now I already have the answer. They are wired in parallel. So that shouldnt have been the problem.

You have some dead diodes but all led strings seems intact. This means:
Strings inside the board have different voltage so the current gets distributed differently between strings. As you see, on the first min dim photo: the strings with more broken diodes are brighter. Maybe theres one or two

When you have current higher this is less apparent. Ask for warranty service and run your boards a little softer in the future.

Rocket Soul said:

You have some dead diodes but all led strings seems intact. This means:
Strings inside the board have different voltage so the current gets distributed differently between strings. As you see, on the first min dim photo: the strings with more broken diodes are brighter. Maybe theres one or two

When you have current higher this is less apparent. Ask for warranty service and run your boards a little softer in the future.

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Thank you. That is very helpfull info. I will email kingbrite tomorrow, I’m redoing my entire setup today. I’ll let you know what kingbrite says about this. Since some people seem to be hating on them, I’ll post it here.

Okay, a little update. I went over to my friend who also has a medical license to grow for her MS. She has three kingbright boards. And what do you know. The V2 versions both are toast aswell.. I went to check them because of what happend to to mine. Now I have one V2 board that works. And the the two V3 (with added 660 nm epistr diodes) boards we own are still runing strongly. So maybe, this is an issue with their earlier boards. I’m now contemplating buying HGL boards and swapping them to this heatsink/driver set-up.

Is there a topic where I can share this info? Is that the “chinese quatum boards knock off builds” topic where this info is relevant?

dendroaspis said:

Is there a topic where I can share this info? Is that the “chinese quatum boards knock off builds” topic where this info is relevant?

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Yeah, that would be the correct place.

Weve seen "batches" of dodgy quality occasionally even from kb/meijiu on some. Warranty given has been erratic: some got new gear or money back some got nothing for litterally the same problems. Personally i dont feel like the china boards should not be run like hlg boards: they are cheap enough to run them arround 60w per board, especially since this approach allows you to use alu sheet for dissipation, which lowers the ali prices and shipping.
Also remember: a broken diode only means about 0.3% increase in wattage per diode. Get warranty if you can, if not you can still go on using the boards but be carefull with the wattage.