Ethernet not enabled on Sierra 10.12.2

Hello,

I had researched that all over the net. I own a few Macs. This one is an iMac12,2. I had tried to remove the /Volumes/mydrive/System/Library/Extensions/AppleKextExcludeList.kext" . I had tried to run the " sudo softwareupdate --background", I had the cable tested with other device, tried a different port etc.

Still I have the following:

Incompatible Kernel Extension Configuration Data:

Version: 3.26

Source: Apple

Install Date: 1/5/16, 4:37 PM

Now, note that most people have this issue with version 3.28.1 but mine says 3.26 and doesn't go away if I delete the files under AppleKextExcludeList.kext nor by doing the softwareupgrade command.

I had also tried to reinstall the OS. And upgraded to the new 10.12.2.

And My ethernet card is dead. I own 4 of these wonderful machines. They all had dual SSDs and I run both MacOS X and Ubuntu on them. The other machines are perfect and I have no issues. This was running great until it stopped. Only the WiFI works both on MacOS X and Ubuntu 16.04LTS. The ethernet is gone.

Therefore:

Is there a proper hardware diagnostic tool for that port?

How to fix this annoying issue? As all the posts, instructions etc I had tried from the posts here and online never fix this issue?

Thank you so much,

CS.