A power outage yesterday left my desktop PC without a wired Ethernet connection. Wi‑Fi still works on my phone and laptop, and the TV's wired connection is fine. I tried reconnecting both ends, using a brand-new Ethernet cable, restarting the router, unplugging the PC and discharging it, running command-line troubleshooting steps, and reinstalling the Ethernet controller through Device Manager. None of that helped. I also tested the PC with the router ports and cable that work for the TV, but the PC still would not connect. Could the motherboard's built-in Ethernet port have been damaged, and would a USB-to-Ethernet adapter reliably bypass the problem?
4 Answers
Before buying anything, check the link lights on the desktop’s Ethernet jack and test the port with a known-working cable and router socket. You can also connect the desktop directly to another device that has a working Ethernet port and see whether either side detects a link. If there are still no lights or detection, the motherboard’s Ethernet chip, port, or a nearby trace may have been damaged by the outage. A PCIe network card is another dependable replacement if you eventually decide to install one.
The outage may have damaged more than just the network port, especially if there are other new motherboard problems such as crashes or missing devices. If the PC is otherwise behaving normally, though, bypassing the integrated controller with a USB adapter is a sensible first test. If several components begin acting strangely, have the motherboard and power supply checked.
A USB Ethernet adapter is a reasonable fix and will usually work independently of the motherboard’s integrated network chip. A PCIe Ethernet card would also restore wired networking, but it requires opening the case and installing hardware, so USB is more convenient in your situation.
Since the same router ports and cable work with the TV but not with the desktop, the PC’s Ethernet port or its circuitry is probably the issue. If there are no link lights on the PC’s Ethernet jack when the cable is connected, that makes hardware failure even more likely. A USB-to-Ethernet adapter should bypass the built-in port and is the easiest option to try.
I tested the cable and router ports that work with the TV, and the desktop still showed no connection. Since the case is difficult to access, I’d prefer trying a USB adapter first.
I’m leaving an internal card as a last resort because the PC is in an awkward spot, but I’m willing to try the USB option if it should bypass the damaged port.