Cable issues vary between devices. Ethernet works on laptop but not on PC.
Cable issues vary between devices. Ethernet works on laptop but not on PC.
I just completed the installation of CAT5e cabling throughout my home, a project done behind the walls so it's difficult to reverse now. I transferred my tower from my parents' house to mine, and suddenly the problem appeared. I checked all the cables and everything seems fine, but when I connect my tower PC to the system it displays 'identifying' and says: "Ethernet" lacks a valid IP Configuration, and the network cable appears loose or damaged. Unless I've used six faulty patch cables, I'm unsure what's causing the issue, especially regarding the IP address. If I connect my tower directly to the ISP router, it functions properly, as do the lower-level CAT5e sockets. My laptop operates on all of them. I've also swapped out the Ethernet card in the PCI-e slot, reset the device, updated drivers, reinstalled it, tried different rooms, used advanced CMD commands but needed an online connection to work and I couldn't access the internet. In my previous home, the WiFi signal was poor, so I didn't install a Wi-Fi card. If you have any networking experts, your advice would be greatly appreciated!
It seems the problem might relate to wiring or signal sensitivity. One NIC functioning while another doesn't could stem from power issues or signal detection differences. Check if the wire is intact or if the jack needs reattachment. Have you used a cable tester to confirm all connections?
I've checked and everything functioned correctly—even after rerunning the tests. I unplugged the cables from another room and it worked immediately. I don’t need the Cat5 in the second bedroom now, but I’ll install a mesh system eventually.
Checking if turning off that single area resolved the issue suggests it might be a localized cable problem or a Switch port concern. If the fix applies to multiple rooms, it likely points to a broader network fault.