Question Ethernet cable not detected when inserted directly into motherboard port, but works fine when passed through TP Link AC1200 router.

[gamer_patriot]

I built a new PC with Asus ROG Strix Z390-E Gaming mother board which comes with Intel Gigabit Ethernet (https://www.asus.com/us/Motherboards/ROG-STRIX-Z390-E-GAMING/). The problem I'm facing is when I insert the Ethernet cable into my MoBo port it doesn't get detected. But when I use it through my TP Link AC1200 router it works fine. So my MoBo port is not problem as it working through router cable and the direct cable is also not problem as its working with the router. Plus I tested the cable by directly inserting it into my Smart TV LAN port and its working.
I tried various solutions from google results like updating BIOS to latest version, disabling and reinstalling drivers for Inlet Ethernet Drivers, unplugging the direct LAN cable and disconnecting pc from power for some time, but nothing worked.

Everything worked fine on my old PC having Asus Z68 motherboard until last week. Plus another problem I'm facing is on this new system is the internet speed is not going beyond 94Mbps through router. My internet speed is 250Mbps and I get this speed on my mobile through WiFi with the above mentioned TP Link router.

Any help to resolve this would be much appreciated - Thanks!

 

[Ralston18]

On your new PC did you disable any wireless network adapters?

And, verify, are you connecting the new PC directly to the router with a known working Ethernet cable? It appears that you have tested the cable via Router <-----> Smart TV but please confirm.

Run and post the results of "ipconfig /all" (without quotes) via the Command prompt.

 

[gamer_patriot]

On your new PC did you disable any wireless network adapters?

And, verify, are you connecting the new PC directly to the router with a known working Ethernet cable? It appears that you have tested the cable via Router <-----> Smart TV but please confirm.

Run and post the results of "ipconfig /all" (without quotes) via the Command prompt.

Hey thanks for taking time to check my problem.

Yes, I tried both things Disabling and Enabling the wireless when using the direct Ethernet cable, none worked (I mean direct cable not detected).

Yes, I've tried the Ethernet cable directly (without router), and its not getting detected. My PC detects the cable only if its coming through Router and gives me reduced speed of approx 94Mbps. And yes the direct Ethernet cable is working, cause I'm using is on the router and tested on my Smart TV by directly plugging it in LAN port.

Putting this to just clear out any confusion - so I have an Ethernet cable provided by my ISP and I've my own TP Link AC1200 router (with 1 Internet Input and 4 Lan Output plus wireless capability of 2.4Ghz & 5Ghz). When I'm connecting my ISP Ethernet cable to my PC its not getting detected but when I'm using the cable from router (after putting ISP Ethernet into router IN and taking one of the OUT cable from router into PC Lan port) its working. Plus my internet speed is restricted to 94Mbps when using Lan from Router while I'm getting full speed of 250Mbps on WiFi @5Ghz.

I've attached the screenshot of ipconfig /all from CMD.

https://drive.google.com/file/d/1KSASj6_P6x_fXoI6RzyiZPSO7HnO_t35/view?usp=sharing

 

[Ralston18]

First: did not note anything in "ipconfig". Other than the lease time being only 4 hours. Normally set to be 24 hours but that is up to the admin.

How is everything connected?

ISP ---->Modem--- ISP Ethernet cable --->[WAN] your TP-Link [LAN]---Ethernet cable --->[LAN] PC

What make and model Modem (or Modem/Router)?

Feel free to correct my line diagram as necessary...

Also, check the configuration settings on the PC's wired LAN adapter. Are Speed and Duplex set to "Auto"?

 

[gamer_patriot]

Hey, so the diagram you provided is not definitely what I've. I just have a cable provided by my ISP which I can directly plug into my PC (if I just want to use 1 device) or I can configure my router with my ISP account to use it for multiple devices with LAN and WiFi. So the diagram would be like this.

ISP Cable ---> IN ---> TP Link Router ---> OUT ---> PC LAN port and WiFi Signal (working perfectly)
ISP Cable ---> IN ---> PC LAN port (not working/ not detecting)

Oh by the way slow speed issue is solved, I changed the cable coming out from router and now I'm getting 250Mbps.

 

[Ralston18]

What is the source of that ISP cable coming in? Who is your ISP?

There should be another device.

Does the following link provide the User Guide for your Router?

If so, refer to the diagram on physically numbered Page 8 of the User Guide.

https://static.tp-link.com/resources/document/Archer_C5_V2_UG.pdf

and also

https://static.tp-link.com/res/down/doc/Archer_C5(US)_V2_QIG.pdf