My Dell OptiPlex 3080 Micro was freshly installed with Windows and the built-in Ethernet connection worked at first, but it stopped working at some point. The PC still connects to Wi-Fi, so I did not notice immediately. The Ethernet cable works normally with another computer. I have already tried resetting Winsock and TCP/IP, performing a hard power reset, reinstalling Windows, resetting the CMOS, checking the BIOS, removing and reinstalling the Device Manager driver, and installing both Realtek and Dell network drivers. Device Manager hides the Ethernet adapter and reports Code 45, while the Realtek installer says the device cannot be found. Scanning for hardware changes does not bring it back, and I cannot find an Ethernet-related option in the BIOS. Could this be a hardware failure, and is there another way to confirm it before replacing anything?
2 Answers
A good way to separate a Windows problem from a hardware problem is to boot a Linux Mint live USB. You do not need to install it; it runs temporarily from the USB and memory. Plug in the Ethernet cable after Mint starts and check whether a wired connection appears. If the adapter is missing there too, especially after all the resets and driver attempts, the onboard Ethernet hardware is probably faulty.
Try a full flea-power drain first. Shut the PC down, unplug the power cable and any other connections, then hold the power button for about 40 seconds. Reconnect everything and boot it again. Dell systems can occasionally rediscover hardware after residual power is completely drained. If the adapter still does not appear, a USB 3.0-to-Gigabit Ethernet adapter is usually the cheapest practical workaround, since replacing the motherboard in a Micro system may not be worthwhile.
So I just need to boot Mint from the USB, connect the cable, and see whether it detects the wired connection automatically?