[SOLVED] Wrong use of screws causing short circuit in brand new motherboard

Aug 4, 2021
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Hello, I am building a new pc for the first time, and just finished installing everything. So as one does I plug in the power to install windows, but when I do that a short circuit occurs and the power fell out. In the midst of troubleshooting I start plugging out cables from the power supply to find what's the issue, the first one I plug out is the CPU power 1, when I did that the pc turned on just fine (RGB fans and RGB ram kicked on). I tried plugging the power to CPU power 2, that didn't fix it. But I just can't figure out what the problem is, everything is new out the box. Here are pics with the pin layout as given bij both manuals:

Power supply CPU pins and Motherboard CPU power pins (first pic is from power supply manual, second one is from motherboard manual)

Here also a list of all (relevant) components:
Motherboard: MSI MPG Z590 GAMING CARBON WIFI
CPU: Intel Core i5 11600K LGA1200 12MB Cache 3.9GHz retail
Graphics Card: MSI 8GB D6X RTX 3070 Ti Suprim X 8G
CPU cooler: be quiet! Dark Rock Pro 4
RAM: Corsair 16Gb Vengeance PRO (2x8Gb)
Power Supply: Delta gps-850hba

I originally wanted to go with a Corsair RM850 as for power supply but the Delta one came free with the GPU so that's why I went with that. But I'm considering going for the Corsair one nevertheless in case that may be the problem.

I think I got everything but if I missed something I'll post it right away, does someone have any ideas as to what may be the issue?
 
Solution
That appears to be the bottom side of you mobo at a mounting hole, correct? The minor damage I see looks like something dragged across part of the hole area and removed part of the metal "finger" pattern on the upper right side, but did not affect the left side at all. There are small marks across the board surface below and to the right of the hole, but those appear to have merely removed a small coating without doing any damage to the underlying traces. I see no evidence of arcing or burning. So I'd expect that this is NOT important damage. However, whatever caused the original mechanical damage to the metal fingers MAY have caused other damage in the area that is not in the photo.
What do you mean "power fell out"?
Did the power supply trip?
It runs with an 8 pin in CPU power 2?
Does it run with an 8 pin in CPU power 1 ONLY?
It trips when both are plugged in correct?
...as a side note.....i would change to the Corsair anyway as I wouldn't trust that power supply with all that expensive hardware.
 
What do you mean "power fell out"?
Did the power supply trip?
It runs with an 8 pin in CPU power 2?
Does it run with an 8 pin in CPU power 1 ONLY?
It trips when both are plugged in correct?
...as a side note.....i would change to the Corsair anyway as I wouldn't trust that power supply with all that expensive hardware.
yea that, the power supply trip (like the one in the main electricity box for the house (sorry english is not my first language).
Furthermore it did not run in either cpu power 1 nor 2.
And while doing some more troubleshooting I can't even get my motherboard to turn on now, so I've decided change power supply and purchased the Corsair RM850. Lets hope that one works better
 
Is it possible that having a power trip many times (about 5/6 times I believe) while troubleshooting could have damaged my motherboard/CPU/GPU, etc? or chances are they are still ok?
 
Delta is an OEM, and generally makes seriously solid psus, most times they are under-rated on the sticker, unlike cheap psus that claims far exceed rated power.

Cpu power cables (EPS) are normally never '8-pin', but 4+4 pin, the pcie will be either 6, 6+2 or 8pin.

The pinout for power pins is very different for EPS and PCIe, so make sure you actually are trying to plug in the correct connections because the protective circuit in the psu will (should) instantly shut the psu down by tripping the short circuit (SC) protection if it's plugged in wrong.
 
yea that, the power supply trip (like the one in the main electricity box for the house (sorry english is not my first language).
Furthermore it did not run in either cpu power 1 nor 2.
And while doing some more troubleshooting I can't even get my motherboard to turn on now, so I've decided change power supply and purchased the Corsair RM850. Lets hope that one works better
The RM850 is a good PSU but I would be looking into what Karadjgne said in the above post.
 
Delta is an OEM, and generally makes seriously solid psus, most times they are under-rated on the sticker, unlike cheap psus that claims far exceed rated power.

Cpu power cables (EPS) are normally never '8-pin', but 4+4 pin, the pcie will be either 6, 6+2 or 8pin.

The pinout for power pins is very different for EPS and PCIe, so make sure you actually are trying to plug in the correct connections because the protective circuit in the psu will (should) instantly shut the psu down by tripping the short circuit (SC) protection if it's plugged in wrong.
I am using the 4+4 pins from delta, and that is what was causing trouble i believe. And i'm sure i plugged everything in correctly. I made sure of it many times by comparing both manuals
 
Are you familiar with stand-offs and how they MUST be positioned properly? An improper stand-off location can cause a short circuit from a trace on the bottom of your mobo to the case mounting panel, sometimes very sensitive to flexing of the mobo. This is a common error in new builds.

If you need details, post back here.
 
Are you familiar with stand-offs and how they MUST be positioned properly? An improper stand-off location can cause a short circuit from a trace on the bottom of your mobo to the case mounting panel, sometimes very sensitive to flexing of the mobo. This is a common error in new builds.

If you need details, post back here.
I am unfamiliar with that concept, would you be so kind as to elaborate?
 
Ok, you are right, I failed to use the stand-off screw as that was (as far as I can remember) not said anywhere in the manual
I can place it now, would that fix my issue, or is my motherboard broken and I need to buy a new one?

Edit 1: just saw this in another thread:

parts from case

I didn't know what most of these were, so I ignored them, I for example did not use the 20 small screws which are labeled in the post as motherboard screws, instead of that I used the 8 HDD screws apparently. I will fix that now, hopefully this did not damage my motherboard nor any other parts

Edit 2:
I took out everything from the case, and I'm unsure as to where I have to place a standoff (I only got one as seen in the pic above). Here below are pictures of the inside of the case, the first one a clean one and the second one I have circled some stuff:

Casing standoffs?

In blue is circled the middle part that seems to the "screw?" where you would place the motherboard so that it hangs in place while you install the rest of the screws.
Then in red I have circled what I believe to be the standoffs that came with the case already but not sure of it (8 of them, 6 visible in the pic with two behind cables)
In yellow is a hole which I do not know what it is for, same is for green (only green also has what looks to be a small screw next to it)
Furthermore I have no idea what to do with the 20 screws I got, as I only see 8 spots to screw in

Edit 3: I also updated the thread name so it matches the issue at hand
 
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Update:
Fixed the screws, replaced the power supply with the Corsair RM850, everything seemed to work (I tested the motherboard before putting it back on the case, then again just after putting it in, everything worked. But after putting everything back together and trying to turn it on, motherboard fried, there was a flash, and smoke and then this happened:
#IShouldHaveGonePreBuild
 
Since you rushed ahead this may be a bit late. Here's how stand-offs work.

Stand-offs usually are small pieces of metal about ¼" long, with a short threaded shaft out of one end, and a threaded hole in the other end. They are used to establish a space between the back side of your mobo and the back mounting plate of your case, so that the mobo does not short out. They are the means of fastening and supporting your mobo in the case.

If you look carefully at the mounting holes in your mobo (often nine in three rows of three) you will see each has several little metal fingers or petals around it. The mobo is designed to be grounded to the case back mounting plate by the screws through these holes and into the stand-offs. BUT the mobo should NOT be touching Ground at any other point. Now, mobos come in several layouts and patterns of mounting holes. So the back plate of the CASE comes with threaded holes for the stand-offs for all possibilities, and the builder MUST place the stand-offs only in the right holes. The rules are:
  1. It is desired to have a stand-off under each mobo mounting holes for good support.
  2. There must NEVER be a stand-off where there is NOT a mobo mounting hole! A stand-off in the wrong place can cause a short circuit to a trace on the back of the mobo.
Some cases arrive with the stand-offs in a bag. Others arrive with them already installed in a common pattern. BUT the builder MUST check the positions and MOVE any that require that. Sequence:
A. Study the mounting hole locations in the mobo.
B. Study the threaded holes in the case back plate, and any stand-offs already in place.
C. Ensure there are stand-offs installed on the case back plate ONLY where they match a mobo mounting hole.
D. Lay the case on its side and place the mobo into the case over the stand-offs. Adjust its position so it is exactly where it will be when finally fastened down.
E. Examine EVERY mobo mounting hole and EVERY stand-off to be sure they match up in all positions. If there is a mis-match, remove the mobo and adjust the stand-off until you get it all right.
F. NOW you can install the screws through the mobo holes into the stand-offs.
 
Since you rushed ahead this may be a bit late. Here's how stand-offs work.

Stand-offs usually are small pieces of metal about ¼" long, with a short threaded shaft out of one end, and a threaded hole in the other end. They are used to establish a space between the back side of your mobo and the back mounting plate of your case, so that the mobo does not short out. They are the means of fastening and supporting your mobo in the case.

If you look carefully at the mounting holes in your mobo (often nine in three rows of three) you will see each has several little metal fingers or petals around it. The mobo is designed to be grounded to the case back mounting plate by the screws through these holes and into the stand-offs. BUT the mobo should NOT be touching Ground at any other point. Now, mobos come in several layouts and patterns of mounting holes. So the back plate of the CASE comes with threaded holes for the stand-offs for all possibilities, and the builder MUST place the stand-offs only in the right holes. The rules are:
  1. It is desired to have a stand-off under each mobo mounting holes for good support.
  2. There must NEVER be a stand-off where there is NOT a mobo mounting hole! A stand-off in the wrong place can cause a short circuit to a trace on the back of the mobo.
Some cases arrive with the stand-offs in a bag. Others arrive with them already installed in a common pattern. BUT the builder MUST check the positions and MOVE any that require that. Sequence:
A. Study the mounting hole locations in the mobo.
B. Study the threaded holes in the case back plate, and any stand-offs already in place.
C. Ensure there are stand-offs installed on the case back plate ONLY where they match a mobo mounting hole.
D. Lay the case on its side and place the mobo into the case over the stand-offs. Adjust its position so it is exactly where it will be when finally fastened down.
E. Examine EVERY mobo mounting hole and EVERY stand-off to be sure they match up in all positions. If there is a mis-match, remove the mobo and adjust the stand-off until you get it all right.
F. NOW you can install the screws through the mobo holes into the stand-offs.
After inspecting my case it does seem every mounting hole has a standoff and there are no standoffs elsewhere. So that should be ok, I can only imagine that what went wrong is that due to all the power trips that happened first because I was using the wrong screws, that when I did use the correct ones and powered it that something went wrong and that ended up melting one of the resistors of my motherboard.
You'd think that with how sensitive this is to something like that, that they would label the screws so that you wouldn't use the wrong ones...

Edit:
I recently noticed this, this is at the back, at the hole where the peg sits (so the middle one), does this mean that the peg was what cause the problem? or am I missing something?

Damaged motherboard
 
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That appears to be the bottom side of you mobo at a mounting hole, correct? The minor damage I see looks like something dragged across part of the hole area and removed part of the metal "finger" pattern on the upper right side, but did not affect the left side at all. There are small marks across the board surface below and to the right of the hole, but those appear to have merely removed a small coating without doing any damage to the underlying traces. I see no evidence of arcing or burning. So I'd expect that this is NOT important damage. However, whatever caused the original mechanical damage to the metal fingers MAY have caused other damage in the area that is not in the photo.
 
Solution
That appears to be the bottom side of you mobo at a mounting hole, correct? The minor damage I see looks like something dragged across part of the hole area and removed part of the metal "finger" pattern on the upper right side, but did not affect the left side at all. There are small marks across the board surface below and to the right of the hole, but those appear to have merely removed a small coating without doing any damage to the underlying traces. I see no evidence of arcing or burning. So I'd expect that this is NOT important damage. However, whatever caused the original mechanical damage to the metal fingers MAY have caused other damage in the area that is not in the photo.
Here is the actual important damage to the motherboard, this is what happened that I still do not know for sure why
Melt damage
 
Yes, clearly that one component burned out from an electrical overload. We can't tell from appearance whether that was a short directly to that component, or to some other location on the mobo. Either way, I doubt very much that you could have that component replaced. Further, there might be other damage elsewhere that is not obvious. Your best solution will be to replace the mobo, unfortunately.,
 
Yes, clearly that one component burned out from an electrical overload. We can't tell from appearance whether that was a short directly to that component, or to some other location on the mobo. Either way, I doubt very much that you could have that component replaced. Further, there might be other damage elsewhere that is not obvious. Your best solution will be to replace the mobo, unfortunately.,
Yes I ordered a new one already, so let's hope next time I succeed in building it correctly and something like this doesn't happen again. Can you recommend a site or something where I can find more information regarding everything I should keep in mind in order to avoid damaging my motherboard again or another part?
 
Recommend ... Not really. This (Tom's) is quite good, but you do need to survey many posts. I'm not sure you can find a single post with all the info, although many of the "stickies" at the top of each forum have lots of advice.

This is NOT a really important point, but I'll tell you a related story to illustrate how really rare odd things can happen. I was building a system and installing / mounting the mobo. Having done that I inspected all around and saw a odd thing. On the back panel of jacks and ports, the stamped metal panel mounted in the case where all the mobo ports stick though holes has small springy metal "fingers" around each hole that are supposed to press against the outside of each port connector from the mobo for grounding their connector shells. One one of these, one "finger" had managed to slip inside the connector area so it was touching contact pins inside the port connector socket. I had to remove the mobo and re-install, careful not to have that happen again.
 
Yes I ordered a new one already, so let's hope next time I succeed in building it correctly and something like this doesn't happen again. Can you recommend a site or something where I can find more information regarding everything I should keep in mind in order to avoid damaging my motherboard again or another part?
You must send this dead mobo back to the shop to replace it free with a new one. You have a lot of videos how to build a PC on You Tube. Just search and learn.
 
I am very happy to say that I am typing this post from my new PC. From further inspection it seems like the problem was a scratch on the backside of the motherboard that cause all my problems. So it was plain user error. Thanks to everyone who took the time to help anyway!