"Network Cable Unplugged" on Ethernet Connection

Let's start at the beginning...
In early November I broke my collarbone which resulted in my being out of work since. Being unable to really sit in my office at my desk (plugged directly into the modem as I typically am via ethernet), I moved my laptop downtairs and began using the built-in WiFi. For little things like checking e-mail, that was just fine, however, because the only good place to sit in my house had a crap signal, the connection would drop constantly and, being the built-in was only 3G, it was slow as dirt compared to what I was used to. After a couple weeks, I simply couldn't take it anymore and went to Amazon to pick up something that could handle 5G. I settled on an "LTERIVER" 1200Mpbs Dual Band Wi-Fi Adapter. The day it arrived was simultaneously fantastic and the bane of my existence since.

I plugged the little adapter into a USB 3.0 port and instantly Windows took care of the rest. STUPIDLY, however, I thought to myself "I wonder if it'd run even better if I installed the driver package that came with it." That was over a month ago and I've been quite literally troubleshooting since.

In short, the driver package (which it turns out is Realtek, just like the built-in Ethernet), included a Wi-Fi management utility. You know, the sort of software that attempts to take over for Windows in managing your connection. Thing is, it didn't work. When it'd launch, it would just blink over and over at me as if it was trying to refresh something but never could. "Ok," I thought. "I'll just kill it. The new adapter was working fine anyway." And thus, I removed it and all was right with the world... until the next day when I needed to plug into my modem via ethernet to do something and, despite my best efforts, the connection continued to say the cable was unplugged. No lights on either side lighting up, I immediately knew something had gotten mucked up in installing the software for the new adapter a couple days earlier. And thus began my personal hell...

The sheer list of things I've tried to resolve this could make the thread scroll for days so I'll summarize the first week of troubleshooting by saying that after everything that failed... I did a complete clean reinstall of Windows 10 (as in... killed the active partition completely so it'd start over fresh) with no change.

Here's what I've tried since (and don't be surprised if you suggest something and I reply that I have done that as well - I've honestly lost track of everything I've tried at this point):

1) Swapped cables (I've tried 4)
2) Plugged another laptop into the modem using the same cable now plugged into mine (with success)
3) Updated/Rolled Back the drivers (Realtek PCIe GBE Family Controller btw) - I've tried 3 driver versions now
4) Went to Half Duplex
5) Enabled/Disabled the Adapter
6) Complete removed and reinstalled the adapter
7) Removed the back from my laptop and ensured there were no loose anythings, and blew things out while I was there
8) Downloaded the Realtek NIC Diagnostic Utility (which locks up or reboots my computer when I click on the "Diagnostics" option in the menu it provides)
9) Disabled all other Network Adapters, including the Microsoft ones (Wi-Fi Direct Virtual and Kernel Debug)
10) Booted into Safe Mode with Networking
11) Disabled the Energy Saving features of the adapter

As I said I'm sure there are other things I've tried but at this point have forgotten. I'd absolutely love it if anyone has some unique ideas. As a reminder, I am working with an absolutely clean install of Win 10 here so it's no longer related to installing the new WiFi adapter or the software associated. At this point I want to be convinced it's a hardware issue but, given I've been running on ethernet for 2+ years without any issues until this new adapter came along... that's a hard pill to swallow.

Help?

Thanks for the response! Alas, yes, according to Windows the adapter is working properly and the only problem is the lack of cable plugged in (again, definitely not the problem).

I tried each of your suggestions and unfortunately no luck! The pins are pristine and disabling everything but Ethernet and rebooting netted no change.

Caledon Ken said:

Can you unplug laptop and remove battery. Then press and hold the power button for 30 seconds. Then leave your device unplugged, no battery and have a coffee or ...... Some devices don't reset properly so I'm, hoping a total lost of power causes a reset.

Tried and failed.

Caledon Ken said:

While this doesn't make sense could you enter your Bios and see if there is a setting for the Onboard Lan. Disable it and save. Reboot. Then enter BIOS again and enable. (Wants to ensure there isn't something in BIOS preventing operation.)

This was one of the first things I thought of as well and unfortunately, outside of "wake on LAN" settings, there aren't any to enable or disable the adapter itself. That said, I did try to enable and disable those settings without any luck.

Caledon Ken said:

You said you tested cable with other device. I think you mention you saw the green and yellow lights when connected to this other laptop. Do you see any lights when you connect to troubled device? For sure the cable is fully seated in troubled laptop. (Okay shoot me for asking)

Yep sure did! Instantly as soon as the cable was plugged into the other laptop(s) (yep I tried 3 in fact) the lights on both ends came on. I've tried a few cables now without any change as well.

Caledon Ken said:

I know you said you did clean install. Did you check TCP/IP settings to ensure that when cable is connected it is not in Static IP mode?Type ipconfig /all and look under ethernet section. It should list dhcp mode.

Yep sure did! In fact I even tried forcing it into Static to see if that'd change anything. Nope!

Caledon Ken said:

While likely not a router have you powered down your router for a minute and then restarted. Like I said, not likely, but something simple to add to your growing list of things you've done.

I suppose that's maybe one last thing I could try but, given every other machine plugged into it using the same cable, on the same port (oh I've tried each of those as well), works flawlessly, I don't see what it could be on the router side.

Caledon Ken said:

I saw one solution was to head to your adapters properties through Network and Sharing and on "Sharing" tab enable sharing.

Ah yes I've even tried that. Starting to think somehow the port has given up on me but it just makes no sense. Windows sees it as existing and working just fine outside of a "missing cable" which I've been lead to believe is typically a driver problem. ....... Which just now got me wondering... I wonder if I partitioned this drive and put another OS on it what results I would have. That's a huge pain in the butt obviously but jesus it would at least tell me if it's hardware or software right?

Thanks once again for the reply! I didn't even think about giving Ubuntu a try... I'll do that today I think. Ultimately I just need to know for my own sanity if it's a hardware issue or Windows being a doofus. I already started looking up USB dongles as a final option but I want to be sure it's what I need before I go there y'know? Thanks again!

Caledon Ken said:

Great. I was doing more reading about settings but came to the conclusion, we need to know hardware or software. Good luck.

I was SO hoping for a miraculous result with Ubuntu but... and I swear my heart broke a bit when I saw it... Ubuntu says the cable is unplugged when I check the Ethernet connection.