How much bending is okay for a fresh purchased mainboard?

[_roman_]

How much bending is okay for a mainboard?


Note: I want to get attention for this question. I did a quick search for this question.

A follow up from my other topic. https://www.techpowerup.com/forums/threads/msi-x670e-gaming-plus-wifi-mainboard-any-good.337884/

I noticed a banana like shape when looking at the side during the assembly stage of my computer. When I look at the edge it was high - low - high. Similar to a banana.

I removed the mainboard and I solved it that I screwed froom the left side to the right side all the screws. So I did not had the bend area in the middle.
The last screw was near the CR2032 cell battery in the corner. Just by pressing with the finger it was several millimeters. The CORSAIR MP 600 pro nvme in the bottom slot with dedicated CORSAIR passive cooler also needed more force than usual for a m2 slot. More force as what I remember from two different MSI B550 gaming edge wifi, one MSI X570 tomahawk wifi or ASUS Prime X670-P mainboard. the CORSAIR MP 600 pro nvme is flat. Maybe the support shoe rubber in the middle of the mainboard is slightly too large and therefore that m2 slot needs more force.

Just curious: Would you also move the bend area to a corner? Screw in that last screw last where the bending is in the corner?

-- Years ago in the factory we had many bend pcb. For testing in the needle adapters i had myself use slight force at the corresponding points to get a valid result. So pcb bending is quite common and happens.

Just curious: Would you keep that mainboard?

-- If you wonder I used a towel so I do not scratch the pc case. I used esd "earth" plug, spiral cable and esd wrist strap all the time while handling that build.

-- I did not test 100% the mainboard. I started with the dp internal graphics. Usually I try to test everything in the first few days as I expect a hidden defect.

Note: Picture was before applying Be-quiet Thermal paste and mounting noctua NH-d15 chromemax cooler.

 

[Bill_Bright]

I note your title says, "How much bending is okay for a fresh purchased mainboard?"

The more accurate question is,

How much bending is okay for a mainboard?

The answer is "zero". It should be absolutely flat. Such bending will create stress in the board which can cause microfractures in the board itself, across circuit traces and within soldering joints. Not good. These microfractures may not occur immediately but can start to appear after several (or just one) heatup/cooldown (expansion/contraction) cycles which occurs during normal use.

I can only think of two reasons it is not perfectly flat. (1) There is a foreign object under the board preventing it from sitting flat on all the standoffs. Or (2) wrong and different size standoffs are used in one or more (but not all) of the mounting points.

Standoffs are NOT just to provide clearance between the bottom of the board and metal case. As seen here, standoffs come in different sizes. There is no single industry standard. Because cases come in different sizes, the correct size (height) standoff is determined by the case maker and is based on the height needed to lift the board up from the case surface to properly align the expansion slots and rear I/O section of the motherboard to the corresponding case access points.

What this means is those standoffs are NOT interchangeable between cases. This is why standoffs come with cases and not motherboards.

My advice is to pull the board out of the case to ensure no foreign object is underneath, and then to ensure you have inserted the correct standoffs for that specific case. All the standoffs need to be the same height, correct height for that specific case, and you need to ensure you have a standoff at every corresponding motherboard mounting point, and ONLY at those motherboard mounting points.

I emphasize ONLY because cases are designed to support 1000s of motherboards. So there typically are more standoff mounting points than there are motherboard mounting points. A standoff in the case where there is no corresponding motherboard mounting point may result in damaging shorts. No standoff where one is needed may result in a lack of support and then undue flexing when mounting the CPU cooler or inserting RAM.

 

[Redwoodz]

I've seen plenty of boards that had a slight warp to it, especially refurbs.

 

[Bill_Bright]

I've seen plenty of boards that had a slight warp to it, especially refurbs.

I don't see why refurbs would be any different - unless parts were cannibalized from several different computers to build one and that's not typical - at least not with my experience with refurbs.

In any case, the OP said, "several millimeters". That is far from "slight".

 

[INSTG8R]

Well I know there have been some Intel boards where there has been some "flex" around the socket with aftermarket cooler mountings.(I may be wrong) I personally wouldn't feel comfortable with anything flexing, it's definitely not normal and long term possibly damaging to traces.

 

[Bill_Bright]

(I may be wrong)

You are not wrong but it was not just Intel. Some really big, heavy coolers came out before motherboard (and case makers) were ready for them. Fortunately, the latest ATX Form Factor standards ensure lots of support in those sensitive areas. But it relies on the user inserting the correct size and number of standoffs.

 

[abysal]

I have an ASRock B650 mATX AM5 board that has a banana like bend (I'm exaggerating a tiny bit) out of the box, but it seemed flat once screwed down in the case. It was bent on the I/O ports side.

 

[Carlyle2020hs]

If it wasn´t the first batch of apex boards at that time i would have given it back due to:

- PCB bending
- long pins that stick too far out at the bottom for my taste:

 

[EarthDog]

It's more common than some people think (not that it's common). Refurb, new.... I've seen plenty from all vendors over the last several years. That said, I'd imagine there's a tolerance from the factory... what that value is, I have no idea.

I don't like looking at a bent board either, lol. But being a hardware reviewer for the last decade, I don't have enough fingers and toes to count how many boards had a slight (talking a couple/few mm or less) bend to it.

 

[oxrufiioxo]

I would immediately return a board with any kind of bend if it doesn't sit perfectly flat on cardboard it's definitely getting sent back.

It's more common than some people think (not that it's common). Refurb, new.... I've seen plenty from all vendors over the last several years. That said, I'd imagine there's a tolerance from the factory... what that value is, I have no idea.

I don't like looking at a bent board either, lol. But being a hardware reviewer for the last decade, I don't have enough fingers and toes to count how many boards had a slight (talking a couple/few mm or less) bend to it.

I kept a Z390 Asus Maximus code with a slight bend and had nothing but issues with it, even if it wasn't from the bend I should have just got it replaced. Since then I just send anything back even with a slight bend. Thankfully it's rare at least to the point where it's obvious.

Asus support was useless of course when I mentioned receiving it that way they denied my rma and said I should have got it swapped.

 

[EarthDog]

Unless it's severe, like the picture above (I'd say 'several' mm, lol), I wouldn't bother returning it. A couple/few mills.... I'm strapping that thing down and never thinking about it again. We put more stress on the PCB surrounding the socket with heatsinks/blocks than we do screwing down a mobo to a chassis.


I'll reach out to my contacts and see if they can share any tolerances (if).

I had an ASUS motherboard that was perfectly flat out of the box, and still flat with everything installed. However, it was bent like crazy a few weeks later when I took it out to replace the stock cooler (Intel i5 2500k) with an aftermarket one. I didn't encounter any functional issues as a result of the bending but it sure was concerning.

I'd say this is normal too. When there's a lot of tension put on the board from mounting the heatsink/block + thermal cycles, I'm not surprised something that was straight without tension then has a slight bend to it with tension after thermal cycling..

 

[Event Horizon]

I had an ASUS motherboard that was perfectly flat out of the box, and still flat with everything installed. However, it was bent like crazy a few weeks later when I took it out to replace the stock cooler (Intel i5 2500k) with an aftermarket one. I didn't encounter any functional issues as a result of the bending but it sure was concerning.

 

[Bill_Bright]

I think I might have misunderstood the issue.

If you meant it was warped out of the box, then a small amount is probably not a problem AS LONG AS it flattened out properly once mounted in the case (with the proper standoffs).

If you meant it was warped after you mounted it in the case (as I first thought you meant) then I stand by my original post and say there should be zero warping.

Sorry if I caused confusion - other than for myself.

 

[EarthDog]

I heard something back from a vendor... clarifying on the first value.......

Tolerance - 15/1000

Possible causes of bending:
1. PCB material issue
2. High Temperatures (not defined)
3. Pressure from other components.

15 1,000th of an inch so........ ~0.4mm?

I also wonder if they'll warp sitting in a hot arse shipping container and that's why we may get some that look like a 'banana'? No clue.

 

[Bill_Bright]

I don't see how they could warp if not mounted UNLESS there already is some torque stresses going on - and if that is the case, I would consider that a manufacturing defect.

Still, less than 0.4mm across the width or length of a board is hardly significant. "Several" millimeters, as noted by the OP in his opening post, however, is a different story.

 

[Sithaer]

I would immediately return a board with any kind of bend if it doesn't sit perfectly flat on cardboard it's definitely getting sent back.

Yep, same here like I've bought some of the most budget mobos out there and also had a RoG Strix mobo once and none of those were bent at all and its the last thing I would want to see on a brand new mobo.

 

[freeagent]

I have 4 Asus AM4, and a single AM5 board, and an AssRock Intel board, all of them are perfect..

All of them had 1000g coolers on, and then the weight of the fans.. no problem.

Something happened on the line and they just sent it through. I guarantee someone saw that before it went into a box.

 

[A Computer Guy]

Was it a banana boat before you put the red thingy on there? I had a board that was flexing a bit but I discovered it was because I forgot to use the plastic washers that came with the monoblock. I would doublecheck that all the standoffs are fully inserted properly too. I got a premium case recently and that ended up being a problem for me that I needed to correct.

 

[lexluthermiester]

The answer is "zero". It should be absolutely flat.

I would not 100% agree. While bending is not optimal, motherboards can withstand a limited amount of it long term. Minor bending is not a big problem.

How much bending is okay for a mainboard?

Most mainboards/motherboards can withstand about 1mm of deflective bending around the CPU socket from center to mount holes without any long term harm. Any more than that will be out of spec for socket standards designs.

Bending inward from case mounting, the ATX stress limit spec is 2.4mm end to end.

Just curious: Would you keep that mainboard?

Based on that photo? You're not exceeding any stress limits for the PCB or circuit traces. So I would say yes, keep it.

I've seen worse bending on perfectly functional systems. No reason to worry much.

If it wasn´t the first batch of apex boards at that time i would have given it back due to:

- PCB bending
- long pins that stick too far out at the bottom for my taste:

View attachment 404234

That's not serious either. Nothing to worry about. Once you screw it down to the case, it'll mostly be straightened out.

 

[A Computer Guy]

What's this?

 

[LabRat 891]

If everything aligns and works after being mounted down flat, I'd keep it and never worry about it again.

I've got an old 1100T + 990FX build sitting next to me that's far more warped, from the owner routing the CPU power cables under the board.

What's this?

View attachment 405091

Many cases have a 'locating key-peg' instead of a standoff. It's very helpful in positioning the board for installation.

However, in this case (pun intended) it may be worthwhile to remove the board, remove the key-peg, and replace w/ a standoff.

 

[Athlonite]

If it wasn´t the first batch of apex boards at that time i would have given it back due to:

- PCB bending
- long pins that stick too far out at the bottom for my taste:

View attachment 404234

That mobo needs to be sent back it's obviously missed the leg clipping stage how it missed QC like that is a good question

 

[ShrimpBrime]

I had an interesting experience once with an Asus M3A. Yes, thats the complete part number.

Was some of my first experiences with liquid nitrogen as a mater of fact. Anyhow, have trouble with CB/CBB issues, got frustrated and disassembled everything from the board and tossed it on the floor.

I have a 22L Dewar. Was about half full and I dumped the lot of it straight on the board. It bent nearly in half like a taco shell.

What made it interesting is that a few days later I actually posted the motherboard up and it worked like nothing happened.

Poor thing went through a tough beating. Even had a bios flash go bad and made a successful recover booting right off the motherboard disk.

So, in my experiences, motherboards can take a bit of bending. Most boards I have do bend when securing a waterblock and the board is only laying on its box opposed to being mounted in a case.

Is it designed to be flexible? No. Does pcb have some natural give to it? Yes. Worst Ive seen is the board bend enough the cpu pads dont touch the board pins on lga. Otherwise, yeah, boards can will and do bend but typically stay in working order.

 

[_roman_]

What's this?

the Fractal Design Meshify 2 has on this position a fixed standoff. I think it was screwless.

It never was an issue. One screw less standoff just in the middle.
~2 years B550 gaming edge wifi
~2 years ASUS prime x670-p mainboard + self added vertical wlan

Quick search.

https://www.reddit.com/r/FractalDesignNA/comments/kb0zrq/meshify_2_is_it_normal_that_the_middle_mb_standof

 

[Bill_Bright]

I would not 100% agree. While bending is not optimal, motherboards can withstand a limited amount of it long term. Minor bending is not a big problem.

Had you read through the thread, and in particular, my post #13 above where I admitted I might have misunderstood the question, you would have seen where I revised my answer - with which I now stand. And that is, out of the box, some "minor" bending is fine. But once mounted in the case, using the proper sized standoffs for that case, the board should lay flat.