[SOLVED] GPU suddenly no longer detected in ANY of my PCI-E slots ?

May 9, 2021
4
1
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Hi everyone!

Around a week ago, I was playing Red Dead Redemption 2 when suddenly my GPU stopped being detected. Upon rebooting my PC, now with display cables connected to my integrated graphics, I found that my BIOS was no longer detecting my GPU at all. To be specific, it wasn't detecting any video card in my PCIE slots, and device manager in Windows was not detecting a display adapter other than my integrated one. Additionally, it's weird because my GPU is lighting up and everything so I'm pretty sure it is getting power, but it is not being detected at all.
I tried the following to no avail:

  • Resetting CMOS
  • Reseating my GPU in the same PCIE slot
  • Trying my GPU in my other PCIE slot
  • Trying a different GPU that was confirmed working in both of my PCIE slots'
  • Swapping out the power supply for a brand new one (the new one is listed below in the specs)
  • Alternating sticks of RAM and testing it out
  • Updating my BIOS to the latest version
  • Setting my BIOS to use the PEG port instead of Integrated graphics
I tried to be as extensive as possible with the resources on hand, but I think I've narrowed it down to either the motherboard or the processor. I'm not sure if it would be the motherboard because I find it very strange that both PCIE slots are suddenly not working, when I've only really used the one the whole time. Anyways I was hoping to see if any of you had a similar problem, and if you could give recommendations on what part to swap. Some next steps I was thinking of were:

  • Check the CPU for bent pins and to reapply thermal paste (haven't done this in years)
  • try taking the MOBO out of my tower and running it outside of it (atop a cardboard box)
  • If the above don't work, I'll just swap out the MOBO then CPU in that order.
Any help is appreciated!

Specs below: (pcpartpicker link)

MOBO: Asus Z-170A
GPU: Sapphire Radeon RX480 Nitro 8GB
CPU: i7-6700K
RAM: G-Skill DDR4-2400 8GBx2
PSU: Corsair RM 850W
OS: Windows 10
 
Solution
And what about the other way around? Can you put your GPU in another system and it works fine?

If this works then likely cause your motherboard has developed a physical fault on the pci-e bus and will need to be replaced. Maybe one of the tracks leading to the PCI-e slots has been broken or come loose.

Trying the motherboard outside the case on a cardboard box is a decent idea. I would thoroughly clean it with isopropyl while you have it out, you never know, sometimes this does the trick.
May 9, 2021
4
1
15
Sorry for the confusion! First post so definitely could have been better.

To answer your questions, the GPU that was confirmed working in another kit was not detected in any of my PCIE slots unfortunately, leading me to believe that my own GPU is not at fault.

The PSU I had before I replaced it is the cooler master extreme Power 600w PSU.
 

TommyTwoTone66

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And what about the other way around? Can you put your GPU in another system and it works fine?

If this works then likely cause your motherboard has developed a physical fault on the pci-e bus and will need to be replaced. Maybe one of the tracks leading to the PCI-e slots has been broken or come loose.

Trying the motherboard outside the case on a cardboard box is a decent idea. I would thoroughly clean it with isopropyl while you have it out, you never know, sometimes this does the trick.
 
Last edited:
Solution
May 9, 2021
4
1
15
And what about the other way around? Can you put your GPU in another system and it works fine?

If this works then likely cause your motherboard has developed a physical fault on the pci-e bus and will need to be replaced. Maybe one of the tracks leading to the PCI-e slots has been broken or come loose.

Trying the motherboard outside the case on a cardboard box is a decent idea. I would thoroughly clean it with isopropyl while you have it out, you never know, sometimes this does the trick.

I actually just tried my original GPU in another system and it was also not detected... which is very strange. I'm having another friend of mine test out the GPU in their kit to see if it's the same case, will keep this thread updated.

I'm also going to try out the confirmed working GPU one more time in my kit more diligently to really test if it is working or not once and for all. Will update this thread with the results of this as well. Will also clean the mobo as you suggested to see if that does the trick!
 
May 9, 2021
4
1
15
And what about the other way around? Can you put your GPU in another system and it works fine?

If this works then likely cause your motherboard has developed a physical fault on the pci-e bus and will need to be replaced. Maybe one of the tracks leading to the PCI-e slots has been broken or come loose.

Trying the motherboard outside the case on a cardboard box is a decent idea. I would thoroughly clean it with isopropyl while you have it out, you never know, sometimes this does the trick.

First off, thanks for everyone for the help. I marked this as the best answer because it was the suggestion that got me closest to figuring out the issue (which unfortunately is me being an idiot).

When I tried out my friend's GPU that he confirmed was working in my own kit, it was a ASUS R9 270x. This is the first time I've ever seen a GPU that has 2x6pin power connectors, and I thought that only one of them needed to be connected for the GPU to work. Turns out that this is not the case, and after plugging in both power connectors, the GPU is working fine in my own kit, meaning that it is not the PCIE slot or motherboard or CPU, it is in fact the original culprit the GPU, which I assume is dead.

RIP RX480, you've done 5 years of good service.

Thanks again to everyone for the help!
 
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DSzymborski

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First off, thanks for everyone for the help. I marked this as the best answer because it was the suggestion that got me closest to figuring out the issue (which unfortunately is me being an idiot).

When I tried out my friend's GPU that he confirmed was working in my own kit, it was a ASUS R9 270x. This is the first time I've ever seen a GPU that has 2x6pin power connectors, and I thought that only one of them needed to be connected for the GPU to work. Turns out that this is not the case, and after plugging in both power connectors, the GPU is working fine in my own kit, meaning that it is not the PCIE slot or motherboard or CPU, it is in fact the original culprit the GPU, which I assume is dead.

RIP RX480, you've done 5 years of good service.

Thanks again to everyone for the help!

Just wish we had better news for you! Or at least better timing, given the GPU prices right now.

2x6 power connectors on GPUs used to be more common. Essentially, 8-pin PCIE connectors weren't yet universal for quality PSUs in the late 2000s. There were always Nvidia GPUs that went 2x6 until the 900 series and for AMD, the 300 series. Now, it's impossible to find a new quality PSU that doesn't have an 8-pin PCIE connector and you probably shouldn't be using any PSU from 2006 with a good GPU, so there's much less need for that. So for GPUs that need the power, a single 8-pin connector will tend to be used instead of two 6-pins.