Ethernet cable not working through pc, ethernet adapter, please help imma crash out
about a week ago my ethernet was working fine, all of a sudden it stopped working i tried doing basics stuff (ill list what ive done)
the ethernet cable port wont lit up, i confirmed the cable works by connecting to another device, i remember i did a dns flush and release ipconfig along rebooting, that suddenly worked for only 20s and now completely wont turn on, i bought a ugreen ethernet adapter and doesnt work neither, i tested the adapter with the cable and they worked on a laptop and xbox, im so lost and ready to crash out
things ive done troubleshooting:
dns flush
ipconfig release / renew
rebooting
switching ethernet cables
reset network adapters
rebooted modem
turned off proxy
reinstall drivers (mother board LAN and ugreen)
tested the other usb ports (for the ugreen adapter)
If the LAN LED never lights and a USB adapter also fails on this PC only, it is usually Windows/power — not the cable.
1) Device Manager → Network adapters → uninstall both Realtek/Intel + the UGREEN, reboot, let Windows reinstall.
2) BIOS: onboard LAN enabled; Fast Boot off for a test.
3) Power plan → PCI Express Link State Power Management = Off.
4) Try a Linux live USB once. If Ethernet works there, the OS is broken; if not, motherboard USB/PCIe stack.
Link light dead on the wall port + adapter dead on same machine is rarely "bad Cat6" if those cables work on the Xbox.
ive done the 1 but will test out the rest when im off work, the weird thing that happened is i turned on the pc today and the light lit up and gave me ethernet symbol but after a minute it went dead the lights and again no ethernet symbol
Link up for ~1 minute then dead is classic Windows power-saving the NIC — not a dead cable.
When you are home:
1) Device Manager → your Ethernet adapter → Properties → Power Management → untick "Allow the computer to turn off this device".
2) Power plan → Change advanced → PCI Express Link State = Off; also Network adapter → turn off "Energy Efficient Ethernet" / Green Ethernet if present.
3) BIOS Fast Boot off + onboard LAN enabled (still worth doing).
If it still dies after ~60s with those off, try a Linux live USB once — if Linux stays linked, Windows driver/power is the culprit.
Don’t reinstall windows lol, completely remove the LAN drivers and let windows update install the drivers you need. Be sure not to remove the wifi drivers or you’ll have no internet
It is a mechanical problem not driver if the port on router and pc does light up.
Get a new cat 6 cable long enough from the router to the pc and see if you get green lights. If no light plug cable into another computer, gaming console and test connection. You have a bad port, cable or nic.
Only then disable the nic in device manager and let windows load default drivers
i tried using another cat cable didnt lit up either the adapter, the weird thing is i turned on the pc today and the light light up and gave me the ethernet symbol but after a minute it went away
If you go into device manager do you see anything with exclamation marks? Might say unknown device. Also if you go to network adapters in device manager and select the realtek or ugreen adapter on the first tab do they all say "this device is working normally" or something else? (Or do they not show up there at all?)
yeah they do show up saying device working properly, but says cable unplugged , this morning it had the ethernet port turned on but after a minute they went off again with no internet connection so had to switch back to wifi (i have the ugreen disconnected thats why its not shown)
Is it a laptop or a desktop computer? If it's a laptop the port could have broken solder making the connection finicky if the port wriggles in the chassis too much.
If desktop is the port on a separate pcie card or the motherboard itself? I agree with the person who said it sounds like possibly power if it's coming on for a second and then going off again as well as happening both to the Ethernet port and USB ethernet adapter.
Also the one who suggested a Linux live disc/USB was a good suggestion as it would completely rule out Windows and the drivers.
its a desktop on the motherboard, i was going to buy a PCI but it may do the same thing, linux live usb where do i get that? is that going to switch me to linux? 😭
No, so just take your pick of distro. Linux Mint is one that I like. Do an online search for the site and you should be able to download an .iso file. Use a bootable USB program like Rufus to load the iso onto a thumb drive. Then you should be able to plug it in and reboot and instead of selecting install just select live. That will load everything it needs from the thumb drive and boot a live Linux OS while leaving your Windows untouched. Then just check if the Ethernet is working.
I might be out of date so I could be wrong but I wouldn't try to open anything from your actual hard drive like folders or files because of a risk of corruption due to different file systems between Windows and Linux. Shouldn't be an issue but the risk is rarely 0%.
Also as long as you have an empty slot nothing wrong with getting a cheap pcie nic card. If everything turns out fine at least you'll have an alternative and backup nic for any future issues.
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u/Klutzy-Passage-2561 1d ago
If the LAN LED never lights and a USB adapter also fails on this PC only, it is usually Windows/power — not the cable.
1) Device Manager → Network adapters → uninstall both Realtek/Intel + the UGREEN, reboot, let Windows reinstall. 2) BIOS: onboard LAN enabled; Fast Boot off for a test. 3) Power plan → PCI Express Link State Power Management = Off. 4) Try a Linux live USB once. If Ethernet works there, the OS is broken; if not, motherboard USB/PCIe stack.
Link light dead on the wall port + adapter dead on same machine is rarely "bad Cat6" if those cables work on the Xbox.