QB324 Warning

If you have purchased any QB324 boards from HLG and have used the supplied screws without nylon washers, then you may be in for a nasty shock - quite literally!

To recap another thread, I was sent two different types of screws with my QB324/Slate 2 combos. No washers were included. Full account here: https://www.rollitup.org/t/quantum-board-short-live-circuit.968781/

HLG's website explicitly says to use washers: https://horticulturelightinggroup.com/collections/quantum-boards/products/qb324-with-slate-2-single-combo

However, when I emailed to ask if washers were needed for both types of screws I was inexplicable told "No". I was also told at various stages one type of screw required washers (black button head screws), the other (silver) didn't.

This is what we found today after one of the QB324s failed. There were at least three shorts on this board and a few more potential issues on other boards that showed the same wear.







I'm compelled to write this because HLG is still telling customers the silver screws they are now sending out to replace the black button-head screws do not require washers and will not contact the copper matrix under the board as they fit inside the matrix.

This is not true, as you can see below:




These are the offending screws that were sent out with the kit:


I will admit right now that I should have known better and should have simply used nylon washers to begin with - despite what HLG initially informed me. But M3 nylon washers are not easy to come by in my part of the world, so I decided to go with "Option B" - I bought some more silver M3 screws without button heads identical to those supplied by HLG. It was only after test fitting that I discovered there is no "Option B".

There is not enough room around the screw holes to prevent a screw head from making contact once they are in place and the boards heat up and cool down, expanding and contracting and eventually wearing away the white matrix cover.

You must use nylon washers with any screws on these boards if you plant to screw them to the supplied heatsinks (or even your own heat sinks).

Thankfully no-one was injured and the boards fired up again after I removed the offending screws.

But you've been warned - learn from my complacency.

A bit of eye candy so you can see what we're doing with the boards. This is one room of two. We were planning to replace all the HPS bulbs with LEDs and were trialing the QB324s in one corner (far left) of the room for a side-by-side comparison.

2 threads because you forgot to use washers and messed up the solder mask...

Yes. If you haven't read either thread, that is probably the conclusion you would likely jump to.

If you did read the thread, you'd note that a) HLG sent the wrong screws, b) HLG didn't include washers, c) HLG advised not to use washers, d) HLG continues to tell customers the new screws won't "mess up the solder mask". . . when they clearly do, e) HLG belated said they would send out nylon washers . . then reneged when they found out where I lived. Of course, they did offer to pay for them if I purchased them myself . . . but given past promises, thanks but no thanks.

Your opinion is duly noted, though.

Prawn Connery said:

If you have purchased any QB324 boards from HLG and have used the supplied screws without nylon washers, then you may be in for a nasty shock - quite literally!

To recap another thread, I was sent two different types of screws with my QB324/Slate 2 combos. No washers were included. Full account here: https://www.rollitup.org/t/quantum-board-short-live-circuit.968781/

HLG's website explicitly says to use washers: https://horticulturelightinggroup.com/collections/quantum-boards/products/qb324-with-slate-2-single-combo

However, when I emailed to ask if washers were needed for both types of screws I was inexplicable told "No". I was also told at various stages one type of screw required washers (black button head screws), the other (silver) didn't.

This is what we found today after one of the QB324s failed. There were at least three shorts on this board and a few more potential issues on other boards that showed the same wear.

View attachment 4166566

View attachment 4166565

View attachment 4166564

I'm compelled to write this because HLG is still telling customers the silver screws they are now sending out to replace the black button-head screws do not require washers and will not contact the copper matrix under the board as they fit inside the matrix.

This is not true, as you can see below:
View attachment 4166563

View attachment 4166562

These are the offending screws that were sent out with the kit:
View attachment 4166568

I will admit right now that I should have known better and should have simply used nylon washers to begin with - despite what HLG initially informed me. But M3 nylon washers are not easy to come by in my part of the world, so I decided to go with "Option B" - I bought some more silver M3 screws without button heads identical to those supplied by HLG. It was only after test fitting that I discovered there is no "Option B".

There is not enough room around the screw holes to prevent a screw head from making contact once they are in place and the boards heat up and cool down, expanding and contracting and eventually wearing away the white matrix cover.

You must use nylon washers with any screws on these boards if you plant to screw them to the supplied heatsinks (or even your own heat sinks).

Thankfully no-one was injured and the boards fired up again after I removed the offending screws.

But you've been warned - learn from my complacency.

Click to expand...

Thanks man! I got these boards and had a issue that couldn't figure out thinking it was a bad board, bet it was this issue.

Prawn Connery said:

Yes. If you haven't read either thread, that is probably the conclusion you would likely jump to.

If you did read the thread, you'd note that a) HLG sent the wrong screws, b) HLG didn't include washers, c) HLG advised not to use washers, d) HLG continues to tell customers the new screws won't "mess up the solder mask". . . when they clearly do, e) HLG belated said they would send out nylon washers . . then reneged when they found out where I lived. Of course, they did offer to pay for them if I purchased them myself . . . but given past promises, thanks but no thanks.

Your opinion is duly noted, though.

Click to expand...

Sorry to see you have been "Screwed" brother - Keep up the building and kick ass growing

The question is how much torque is required to destroy the solder mask.

Yikes, serious safety issue, especially with multiple boards affected....... this needs to be addressed asap. Tightening (within reason) an included screw should not short, ever.

You did the right thing with this psa....

Starting to remind me of the great HeavenBright debacle

OneHitDone said:

Starting to remind me of the great HeavenBright debacle

Click to expand...

To be fair AP's design issues where another level completely....

Bubblin said:

The question is how much torque is required to destroy the solder mask.

Click to expand...

The answer is, as tight as the screws need to be to fix the boards flatly and evenly against the heatsinks so that they can do their job without creating any air gaps that don't conduct heat away as efficiently.

Screws should never been supplied in the first place if they overlap the matrix, because it will always be a risk.

You can trust me that I did not apply any more pressure than was necessary - which is why all four boards fired up without any issues upon completion.

You can also trust that after numerous on/off (heating/cooling) cycles, the boards expanded and contracted, each time rubbing against the screws and slowly working the matrix mask off, which is what happened in this case.

One of the boards failed after it shorted. Interestingly, the other boards all showed signs of initial shorting, but the heat generated by the screws coming into contact with the copper matrix underneath must have melted and redistributed the white matrix mask material, as those boards did not remain shorted (but showed signs of burning, as in the above pix).

Also, if you look closely, you can see I did use flat metal washers with the silver screws that were supplied, but not the black screws. The metal washers have not caused any problems, as they distribute the torque over a wider area, plus the act of physically screwing the screws in means they chafe the washers and not the board underneath.

I assumed the black button-head screws would also spread the load. None-the-less, I enquired with HLG before I used them and was told the black screws did not need washers.

That is the purpose of this thread: buyers are being sent dodgy screws and given incorrect guidance on how to mount the boards. HLG has a duty of care to its customers and if it is supplying mounting hardware, then that hardware needs to be safe to use.

What happens if someone is electrocuted? Two of these boards in series draw 216V

booms111 said:

Thanks man! I got these boards and had a issue that couldn't figure out thinking it was a bad board, bet it was this issue.

Click to expand...

Have a look for small burn marks around the mounting screws. I'm sorry to hear you had the same problem. I wonder how many others have?

Prawn Connery said:

Have a look for small burn marks around the mounting screws. I'm sorry to hear you had the same problem. I wonder how many others have?

Click to expand...

If I were HLG I'd be stuffing envelopes right now with proper insulating washer/screw assemblies and sending them out to every single person that had purchased boards of that build design just as a precaution.
You know, as auto manufacturers do with recalls to cover their ass even though not all units will fail.
What if someones house goes up in Flames?

OneHitDone said:

What if someones house goes up in Flames?

Click to expand...

HLG has a new owner after the lawsuit?

Prawn Connery said:

The answer is, as tight as the screws need to be to fix the boards flatly and evenly against the heatsinks so that they can do their job without creating any air gaps that don't conduct heat away as efficiently.

Click to expand...

Actual air gaps = use thermal paste.

It could be a shit solder mask, thermal expansion, incorrect hardware/screws, over tightened screws - or all of the above.

My only gripe with the thermal expansion theory is that the expansion itself is relative to the size of metal in question, n we're talking about a pretty small chunk of aluminum. Expansion without a doubt contributed to it, but it's probably in the .0000100" range per c, per Lin foot.

Anyway, I'm blazed af now bla bla bla lol - non conductive washers would be an easy solution - and substantially better instructions from HLG.

Prawn Connery said:

A bit of eye candy so you can see what we're doing with the boards. This is one room of two. We were planning to replace all the HPS bulbs with LEDs and were trialing the QB324s in one corner (far left) of the room for a side-by-side comparison.
View attachment 4166573
View attachment 4166574

Click to expand...

Sorry to hear of the troubles mate but that is a fine lookin room right there

OneHitDone said:

If I were HLG I'd be stuffing envelopes right now with proper insulating washer/screw assemblies and sending them out to every single person that had purchased boards of that build design just as a precaution.
You know, as auto manufacturers do with recalls to cover their ass even though not all units will fail.
What if someones house goes up in Flames?

Click to expand...

As mentioned, initially they offered to send out some nylon washers and then reneged when they found out I didn't live in the US. To pinch a few pennies they suggested I should buy them myself and they would pay for them. Quite how they were going to pay for them I don't know, considering they didn't keep their promise to send the washers in the first place.

That's one of the things that really annoyed me. Nylon washers weigh fuck all and it would cost only a few dollars to put them in an envelop and post overseas.

Bubblin said:

Actual air gaps = use thermal paste.

It could be a shit solder mask, thermal expansion, incorrect hardware/screws, over tightened screws - or all of the above.

My only gripe with the thermal expansion theory is that the expansion itself is relative to the size of metal in question, n we're talking about a pretty small chunk of aluminum. Expansion without a doubt contributed to it, but it's probably in the .0000100" range per c, per Lin foot.

Anyway, I'm blazed af now bla bla bla lol - non conductive washers would be an easy solution - and substantially better instructions from HLG.

Click to expand...

There are no instructions with the boards.

The boards are 3mm thick. When I build Samsung strip frames - and I've built five so far, not including the QB builds - I always leave enough room around the strips to expand and not compress against the u-channel alloy (pic below). Two of the QB324s were perfectly flat and did not require much effort to seat them against the heatsinks. Two of the boards were not perfectly flat, and so required a little extra effort to seat them metal-to-metal (flatten them out). That's why I used metal washers in middle.

You see I use brass washers on the strip builds, too, but they always fall inside the matrix. With the QBs, I had no choice - there is almost no matrix clearance around the mounting holes - that's part of the problem, it's not a good design. However, nylon washers would be an easy fix and should have been included with the mounting hardware. HLG should also not be advising not to use washers when customers enquire. I'm starting to repeat myself - sorry.

klx said:

Sorry to hear of the troubles mate but that is a fine lookin room right there

Click to expand...

Cheers, I designed and helped set that room up for a long-time commercial friend. He insisted on using HPS - because that's what he knows - but we agreed we'd try some LEDs in a side-by-side grow to see how they performed. What attracted me to the QB324s was the spectrum - lots of red around the 660nm spectrum using half CRI90 and half CRI80 3000k chips.

The strain is Paradise Seeds Wappa, and this room produces minimum 6-7lb a month with 4800w HPS (currently 3600w HPS, 800w LED). He has another room that I helped set up, and I have my own personal grow at home which is 400w LED strips and has produced up to 1.5lb per cycle so far (some of my plants run 10+ weeks, others 8 weeks).

One of the interesting things we've found is that the extra red makes a difference in veg, as well as obviously flower. The 4000K strips have been vegging better than the 5000k without any real additional stretch, which surprised me. I guessed they would grow faster, but thought they might stretch more.

Prawn Connery said:

Cheers, I designed and helped set that room up for a long-time commercial friend. He insisted on using HPS - because that's what he knows - but we agreed we'd try some LEDs in a side-by-side grow to see how they performed. What attracted me to the QB324s was the spectrum - lots of red around the 660nm spectrum using half CRI90 and half CRI80 3000k chips.

The strain is Paradise Seeds Wappa, and this room produces minimum 6-7lb a month with 4800w HPS (currently 3600w HPS, 800w LED). He has another room that I helped set up, and I have my own personal grow at home which is 400w LED strips and has produced up to 1.5lb per cycle so far (some of my plants run 10+ weeks, others 8 weeks).

One of the interesting things we've found is that the extra red makes a difference in veg, as well as obviously flower. The 4000K strips have been vegging better than the 5000k without any real additional stretch, which surprised me. I guessed they would grow faster, but thought they might stretch more.

Click to expand...

Really nice clean room just how I like to see a room. I use the same bunnings alu square tubing and same hydro shop plastic trellis in my rooms. Cheap and good.

I switched out a 400W HPS for dimmable 2 x 200W diy strip lights in my mum area and ended up with 4000k because they were out of stock of 5000k and 6500k so was just dumb luck but worked out well.

Bubblin said:

Actual air gaps = use thermal paste.

It could be a shit solder mask, thermal expansion, incorrect hardware/screws, over tightened screws - or all of the above.

My only gripe with the thermal expansion theory is that the expansion itself is relative to the size of metal in question, n we're talking about a pretty small chunk of aluminum. Expansion without a doubt contributed to it, but it's probably in the .0000100" range per c, per Lin foot.

Anyway, I'm blazed af now bla bla bla lol - non conductive washers would be an easy solution - and substantially better instructions from HLG.

Click to expand...

I definitely agree you shouldn't be pulling up gaps with the screws, even on my samsung strips I could tell it was gonna be too tight if I tried to do that. Some double sided thermal tape fixed that problem though.