You only tried the onboard LAN, correct?

You might try using a different network card. I have a gizmo that I ordered from china for a couple $. It's a USB ethernet adapter, and works fine. Not as fast as a real network card or even the onboard network, but very handy and might be useful to see if it's just the network inputs that are damaged.

Here's some examples:

https://www.ebay.com/b/Usb-To-Ethernet-Converter/44932/bn_7023395195

The one I ordered was about $2.50, including shipping, but I got it from china, so took about a month. You can probably find a US seller for a little higher cost.

Hoping things work out and not too much damage.

Yeah, well, it was just a thought. I hope you get it working, but if the USB networks don't help, I wonder if the lightening may have done some more serious damage.

Good luck with the new ryszen system.

Your wife will surely understand the new strange stuff you got.

The network card is toast, literally. Pick up a usb network adapter cheap anywhere. Remove the fried card and use the usb adapter. Anything that was connected by cable gets destroyed by a lightening strike. Look for one that has the same service as your router--N or AC. N is cheaper. The network card slot on the system board could be damaged too.

Don't forget-

 https://answers.microsoft.com/en-us/windows/forum/all/windows-7-support-will-end-on-january-14-2020/103f68c5-c977-42b6-9f9f-3d1ea4c652d9 

He tried a usb wifi adapter and had problems (BSOD, etc.). I wonder if the machine might have some other damage that he hasn't been discovered yet. Lightning is bad business even if it isn't a direct hit. A close strike can induce huge currents in small conductors.

Yeah, the adapter unfortunately caused some issues. I sourced a new motherboard off of Ebay from a supposed known working 7010, so once that gets here I can troubleshoot further. I'm hoping the board fixes the issue, and will report back here. 

Thanks for the help and suggestions. Thankfully the harddrive is still running perfectly, and HD Sentinel and the Dell diagnostics give it 100% health, so at least my files are safe if I do need to go the route of a new build. Don't want to drop the money on that though if I don't have to. With the exception of the Dell case being horrible for cooling, this thing is a workhorse with the upgrades I've done to it. I primarily use it for audio recording, mixing and mastering, so it does that quite well! 

Good luck. It may be that only the input circuits were damaged. Only time will tell.

Don't worry about old savvy; he bounces back faster than Tonto.

Savvy is from another planet so nobody can understand his gibberish. Mars I think was his birthplace.

.

In for an update!! I just installed the "new" motherboard ($13 bucks from Ebay so it was worth the dice-roll) and guess what? I have LAN again!! I just finished up tweaking all of the settings in the BIOS to match the original configuration of the old MOBO, and all is working properly with the exception of the USB 3.0 ports. Granted, these never worked since I got the machine and with the old MOBO, so it's possible that the ports on the case are bad, or there is something weird going on with Windows 7 and the drivers. I'm reinstalling all of the drivers for the USB Ports now, and am going to see if that helps. I do have all of the USB 3 ports enabled in the BIOS, and they are all showing up active in Device Manager, they just don't do anything when I plug in a device. If I plug my Galaxy S8 in for example, it registers that it is slow charging, but will not pop up as a device recognized by the PC like it does if I plug it into a USB 2.0 Port. I can live without USB 3, because like I said they never worked (neither front nor back ports) since I got the machine. . . Thanks for the help troubleshooting, but it looks like I am up and running once again!! Side question, are there any aftermarket cases that an Optiplex 7010 MT motherboard will transfer to AND play "nice" with? I've heard that the Dell screw holes don't line up with a standard Micro ATX/ATX case, and there may be some issues with the headers, but assuming I bring the headers over from the 7010 case and use those in a "modular" style case, would that be plausible? I'm really asking because I need more cooling than what the case can offer me. Audio recording frequently brings my CPU temps up over 70+ degrees C while exporting, and while that's far from the Core i5's TJMaxx, I would much rather see things hover around the 50 degree C range like my old build did. There really isn't any room for an AIO CPU cooler, and my GPU temps are always really high in this case. Totally understand I'll have to bring over the Dell temp sensor, likely the rear fan, and some of the small devices in the Dell case, but has anyone done this? . . FYI I traced back the Dell CPU fan header and made a custom header that I have a fan power bank plugged into, so the computer thinks I'm still using the stock dell cooler when I'm not. I have ports for 4+ fans on that board, and also plenty of power inputs from my EVGA, it's just a matter of "can" I make this motherboard work in a different case? . . Sorry for the long post, thanks again for your help!

Sounds awesome!  By any chance do you have photos?