Mobo network LAN issues

[FOX76255]

Hello once again, something weird is happening with networking and it's driving me up the wall, and I really hope someone can help me.

A few months back, my internet connection went down...except it didn't. Internet kept working, but the ethernet decided to disconnect itself. I ran the windows troubleshooter and it found and resolved the problem, stating that "default gateway was missing".
Everything was ok for a while, fast forward a few weeks, the same thing happened again, same troubleshooting result and summary.
It happened a few more times until about 30 minutes earlier when ethernet decided to call it a day.
No matter what I try, I can't connect to my modem using the ethernet cable. I am confident the cable itself is in good condition, as the network centre identifies the target network, just fails to connect to it. I've tried various other things like updating network card/chipset drivers but those always claim that the drivers are already up to date.
I tried to manually put in missing information in IPv4 config but windows jumps in going "nah, that's all wrong, let me run the troubleshooter, delete your manual input and not solve the problem anyway ".

So yeah... I'm at my wits end here, any and all help will be greatly appreciated as to what even is going on.

EDIT: Completely forgot to say, this is on win10 pro, computer bought from PCS in june, everything worked fine until the "missing gateway error" started showing up for no reason.

 

[SpyderTracks]

Hello once again, something weird is happening with networking and it's driving me up the wall, and I really hope someone can help me.

A few months back, my internet connection went down...except it didn't. Internet kept working, but the ethernet decided to disconnect itself. I ran the windows troubleshooter and it found and resolved the problem, stating that "default gateway was missing".
Everything was ok for a while, fast forward a few weeks, the same thing happened again, same troubleshooting result and summary.
It happened a few more times until about 30 minutes earlier when ethernet decided to call it a day.
No matter what I try, I can't connect to my modem using the ethernet cable. I am confident the cable itself is in good condition, as the network centre identifies the target network, just fails to connect to it. I've tried various other things like updating network card/chipset drivers but those always claim that the drivers are already up to date.
I tried to manually put in missing information in IPv4 config but windows jumps in going "nah, that's all wrong, let me run the troubleshooter, delete your manual input and not solve the problem anyway ".

So yeah... I'm at my wits end here, any and all help will be greatly appreciated as to what even is going on.

EDIT: Completely forgot to say, this is on win10 pro, computer bought from PCS in june, everything worked fine until the "missing gateway error" started showing up for no reason.

Hiya, hope you don't mind, I split this one off as the previous had run for a little while with a break.

Can you post the full specs from the order page so we can see the build again?

Thanks

 

[FOX76255]

There you go:

Case
FRACTAL MESHIFY 2 COMPACT BLACK GAMING CASE (Window)
Processor (CPU)
AMD Ryzen 5 5600G Six Core CPU with Radeon™ Graphics (3.9GHz-4.4GHz/19MB CACHE/AM4)
Motherboard
ASUS® TUF GAMING B550-PLUS (DDR4, USB 3.2, 6Gb/s) - ARGB Ready!
Memory (RAM)
16GB Corsair VENGEANCE DDR4 3600MHz (2 x 8GB)
Graphics Card
8GB AMD RADEON™ RX 6600 - HDMI, DP - DX® 12
1st M.2 SSD Drive
500GB SAMSUNG 970 EVO PLUS M.2, PCIe NVMe (up to 3500MB/R, 3200MB/W)
1st M.2 SSD Drive
1TB INTEL® 670p M.2 NVMe PCIe SSD (up to 3500MB/sR | 2500MB/sW)
Power Supply
CORSAIR 850W RMx SERIES™ MODULAR 80 PLUS® GOLD, ULTRA QUIET
Power Cable
1 x 1.5 Metre UK Power Cable (Kettle Lead)
Processor Cooling
CoolerMaster Hyper 212 (120mm) Fan CPU Cooler Black Edition
Thermal Paste
STANDARD THERMAL PASTE FOR SUFFICIENT COOLING
Sound Card
ONBOARD 6 CHANNEL (5.1) HIGH DEF AUDIO (AS STANDARD)
Network Card
10/100/1000 GIGABIT LAN PORT
USB/Thunderbolt Options
MIN. 2 x USB 3.0 & 2 x USB 2.0 PORTS @ BACK PANEL + MIN. 2 FRONT PORTS
Operating System
Windows 10 Professional 64 Bit - inc. Single Licence
Operating System Language
United Kingdom - English Language
Windows Recovery Media
Windows 10 Multi-Language Recovery Image - Supplied on USB Drive
Office Software
Microsoft® Office Home & Student 2021 (1 Digital License)
Anti-Virus
NO ANTI-VIRUS SOFTWARE
Browser
Microsoft® Edge
Warranty
3 Year Silver Warranty (1 Year Collect & Return, 1 Year Parts, 3 Year Labour)
Delivery
STANDARD INSURED DELIVERY TO UK MAINLAND (MON-FRI)
Build Time
Standard Build - Approximately 5 to 7 working days
Welcome Book
PCSpecialist Welcome Book - United Kingdom & Republic of Ireland
Logo Branding
PCSpecialist Logo
Price: £0.00 including VAT and Delivery
Unique URL to re-configure: https://www.pcspecialist.co.uk/saved-configurations/amd-am4-gen3-pc/wuCVHeJcqq/

CPU and case were changed after placing order; 5600G to 5600, fractal meshify to corsair airflow 5000D

 

[SpyderTracks]

Thanks.

So very first thing, if you look where the cable enters the motherboard, are you seeing green or orange lights at all? Are they flashing?

 

[FOX76255]

Funny story, I'm colourblind so my observation might be wrong. But from what I see, the left light [if you look at the connector sideways] is flashing, the right one stays on all the time.

 

[SpyderTracks]

Funny story, I'm colourblind so my observation might be wrong. But from what I see, the left light [if you look at the connector sideways] is flashing, the right one stays on all the time.

That's fine, colour doesn't really matter, but it shows us that the cable is securely connected, so we can rule out that for now.

The next thing I would personally do which may be a quicker approach:

If you open device manager (just type it into search)

Goto network adapters

Find the LAN driver which will be something along the lines of Realtek RTL8125 LAN

Right click it and click uninstall device

Then reboot PC.

What that will do is fully uninstall the driver, then when you reboot, it will automatically reinstall it fresh.

IF that works, first thing that's worth doing is go into Windows Update and search for any updates.

Let us know how you get on.

 

[FOX76255]

I've done all of that, but windows claims that a driver from 2015 is up to date, it also said the same thing about a 2019 driver that came with this system.

 

[SpyderTracks]

I've done all of that, but windows claims that a driver from 2015 is up to date, it also said the same thing about a 2019 driver that came with this system.

So it's connected to the internet after reboot?

 

[FOX76255]

Nope, I have to use a little wifi dongle to connect to my router, ethernet flatout refuses to work even though network sharing centre sees my router and its name after punching in IP/DNS/gateway/etc manually. Defaults, ie "obtain address automatically" etc end up showing "unidentified network".

 

[SpyderTracks]

Nope, I have to use a little wifi dongle to connect to my router, ethernet flatout refuses to work even though network sharing centre sees my router and its name after punching in IP/DNS/gateway/etc manually. Defaults, ie "obtain address automatically" etc end up showing "unidentified network".

So sorry, did you follow those steps? And it still won't connect after reboot?

Are there any other devices connected to the router via LAN?

 

[FOX76255]

I followed your steps to a T, uninstalled the controller and its drivers, rebooted, windows reinstalled them again, ethernet doesn't work even though it would appear to "physically" work.
No other devices are connected to the modem, which is a TP Link ADSL/VDSL modem, not a router. My bad if that's caused misinformation.

 

[SpyderTracks]

I followed your steps to a T, uninstalled the controller and its drivers, rebooted, windows reinstalled them again, ethernet doesn't work even though it would appear to "physically" work.
No other devices are connected to the modem, which is a TP Link ADSL/VDSL modem, not a router. My bad if that's caused misinformation.

Have you tried rebooting the router?

It would suggest that the issue is with the router not supplying a DHCP IP address

 

[FOX76255]

I'll give that a try, though desktop's IP is set to never expire, and the wifi dongle gets an IP without issues so idk, but I'll have a go and post back. If you have any other troubleshooting steps to try, please post them.

EDIT: on a hunch, I dug up the BT smart hub I was given 2 years ago, plugged it in and voila. Everything works now. I guess the TP Link modem was on its way out and that's where the ethernet issues came from. Other than that, your help was greatly appreciated and sorry I kinda wasted your time with a dead end.