Question New GPU is not detected by computer when plugged into a PCIe slot ?

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Jan 17, 2025
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I have made a build with specifications i5-12400, Gigabyte GTX 1080, ASUS PRIME B660M-K D4, Corsair RM650x (2016, from old setup) and the GPU is not at all detected by the computer, not even in Device Manager or BIOS. It works when using a m.2 to PCIe adapter, and I have tested other GPUs in the same slot to no avail. The motherboard only has one PCIe x16 slot.

I have tested 3 other motherboards also. Two MSI motherboards don't POST no matter what I do and another ASUS board has the exact same problem.

I have also tested using a different no-name power supply that I had laying around and still had the same problem. Any suggestions?

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Just wondering from looking at the OP's first picture is he using the correct PCI-E cable in the power supply.

The one to the left that says Peripherals & SATA the cable says TYPE-4 and blurry so does the cable he has plugged into the PCI-E power block also says TYPE-4.

If this is just how the manufacture labels them and if this is fine disregard but if there indeed incorrect he could be popping every GPU that get that wrong plug. Again I'm not sure if just confusing wiring labeling or is this the heart of the issue.
 
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Again I'm not sure if just confusing wiring labeling or is this the heart of the issue.
RM650x PSU connectors:

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Based on that, both "Type 4" cables are connected to PCI-E slots, since top row, from left to right, is: 2x SATA, 3x PCI-E.
And in top row, counting from left, OP has 3rd and 5th cable plugged in. One is for CPU another for GPU.

Another way to tell is counting wires that go into the connector on PSU side. It is clearly seen that 3rd connector has 4 wires on top row (8 in total), which only fits into PCI-E connector. SATA connector has 3 wires on top (6 in total).

"Type 4" is the overall cable type naming for Corsair. E.g some newer Corsair PSUs are using Type 5.
 
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Just wondering from looking at the OP's first picture is he using the correct PCI-E cable in the power supply.

The one to the left that says Peripherals & SATA the cable says TYPE-4 and blurry so does the cable he has plugged into the PCI-E power block also says TYPE-4.

If this is just how the manufacture labels them and if this is fine disregard but if there indeed incorrect he could be popping every GPU that get that wrong plug. Again I'm not sure if just confusing wiring labeling or is this the heart of the issue.
The GPU is plugged into the 3rd slot (dual 6+2), CPU is plugged into 5th slot (to 8-pin), one SATA power in 6th and motherboard power in last slot. AFAIK it is how they are supposed to be inserted.
 
  • Like
Reactions: stonecarver
Just wondering from looking at the OP's first picture is he using the correct PCI-E cable in the power supply.

The one to the left that says Peripherals & SATA the cable says TYPE-4 and blurry so does the cable he has plugged into the PCI-E power block also says TYPE-4.

If this is just how the manufacture labels them and if this is fine disregard but if there indeed incorrect he could be popping every GPU that get that wrong plug. Again I'm not sure if just confusing wiring labeling or is this the heart of the issue.
I have checked this but one of the GPUs I tested did not require external power and was still not detected, meaning it's likely not the problem
 
GPU that doesn't work in two different working systems is considered bad (dead). Testing the same GPU in 3rd, 4th etc systems is futile.

MoBo that doesn't detect known to work GPU, is considered faulty. Testing 2nd GPU solidifies the conclusion. Testing 3rd, 4th etc GPU is futile.

OP has tested what? 3x GPUs? 4x MoBos?

Bad CPU, which would otherwise boot to OS, would throw BSoDs. Usually, when CPU is bad, system won't POST at all.
With RAM, this can be validated with memtest86. 4 full passes (15 different tests per pass) is considered acceptable. If no errors - RAM is sound.
Link: https://www.memtest86.com/

Though, to use all possible data patterns, Test #6 needs 32 passes. No one in their right mind is going to do 32 full passes of memtest86, since depending on RAM amount, it takes days. (E.g 1x DIMM of 8GB for 32 passes would take ~1.2 days, or 32 hours. 2x 8GB and 32 full passes would take ~80 hours).