I've recently upgraded my home network and added a 2.5gb NIC to connect directly to my router (Ubiquity DR7). Initially, it worked fine with the built-in network jack on my motherboard (ASRock H 470 Phantom Gaming 4). However, after installing two different NICs in my open PCIe slots, my system completely stops working - it won't turn on at all. I've tried powering down and removing all components except for the essentials, but still no luck. The only way to get the computer to power on again is by unplugging and re-plugging the power connector to the motherboard, but this only works if the NIC is removed. I'm stumped as to why this is happening and how to fix it.
2 Answers
What specific NIC models did you try? It's important to check that they’re compatible with your motherboard. Sometimes cheaper models can cause issues. Additionally, a short circuit in the PCIe slot could be the culprit, preventing your system from powering on.
It sounds like there's a possibility that your NIC might be shorting out the PCIe slots. It isn’t super common, but it can happen, especially with cheaper components. Have you checked if the NIC is properly seated? Also, consider testing the NIC in another system if you can or trying a different slot.
That's a valid thought! If the SATA card works fine in the same slot, it's odd that the NIC would cause issues. I’ll make sure it's seated correctly and maybe try testing it on another setup.

I tried a YuanLey and a QFly model. I figured since it's an easy upgrade, it shouldn't cause issues. But now I'm wondering if I need to invest in a better-known brand to avoid problems.