Have you checked if your motherboard's NIC is functioning properly?
Have you checked if your motherboard's NIC is functioning properly?
Your Ethernet connection was fine last night but is now failing in the morning. The lights on the router and the NIC are blinking correctly when you connect the cable, yet Device Manager doesn’t list the Intel I225 adapter. The troubleshooting steps suggest using an Ethernet cable, but after installing firmware and drivers it still doesn’t appear. Clearing CMOS didn’t help. Is the device completely nonfunctional?
Removed the CMOS and it still isn't visible in Device Manager? It could be that the chip is faulty. You might want to try starting with a Linux USB drive to check available devices, which offers more tools for testing but may require some technical guidance.
Consider a different cable and operating system. Network interface issues are rare, though. In the worst case, they might cost around $13 on Amazon. https://amzn.to/2RZttih
Having spent many years on ITX builds, I often questioned my next steps. I’d likely attempt to return the motherboard via RMA, or switch to a USB3 NIC if needed.