New MSI Z790 LAN port issues

gillmanjr

Member
Hey all. Got the rest of my new components yesterday and finished my new build. MSI Z790 MAG Tomahawk DDR5, 13600k, Corsair Dominator DDR5-5600, Samsung 990 Pro NVME, RTX 4070 ti. For the most part everything went OK but I have had issues with the LAN port on the new MOBO and I am really baffled by this. I was wondering if anyone might be able to provide insight. Here goes:

When I first powered up the new machine yesterday I saw the lights on the LAN working. Then when I started the Windows 11 install they went away and wouldn't come back. No ethernet connection even though I KNEW it was working. I literally spent hours troubleshooting. I basically threw the book at it, re-installed the drivers from MSI website several times, changed network settings, uninstalled the drivers and shut down the PC, performed a network reset both from within Win11 and a winsock reset from cmd, cleared CMOS, etc etc. I even chatted with MSI tech support and they had me try some things. NOTHING WORKED. Then I shut down the PC overnight and when I turned it on today, the LAN port worked and I had ethernet connection. WTF! I didn't even do anything other than shut it down. It was the first time I actually had a hard wired ethernet connection on this machine. After that I reset the PC and went into BIOS to enable XMP for my RAM and OC the i5 (slightly), when I exited BIOS and back into windows, LAN port was down again. So I again SHUT DOWN the PC (not a reset, a shut down), and actually unplugged the power cable for a few seconds and then plugged it back in and started it back up...LAN port working again. I actually went though this cycle twice to confirm. It appears that even if I enter the BIOS (and not even make any changes) and then exit to windows, the LAN port doesn't work. It will then work again only if I shut down the machine (a reset won't do it). Any ideas on this one? I have obviously googled this and read that there are known stability issues with the latest Intel network driver that I am using, is that what I chalk this up to and just live with it (for now)?
 

johnb35

Administrator
Staff member
A couple things here.

1. When you built it, did you make sure to use the standoffs between motherboard and case if case requires them? You could be shorting out somewhere causing the problem. Also make sure that there are no metal tabs from the I/O plate sticking into the network port.

2. Are you running the latest bios version? which is 7D91VH2

3. Go here and use the Intel support assistant to see if there is an updated driver for the ethernet port. https://www.intel.com/content/www/us/en/support/intel-driver-support-assistant.html

They are having problems with that lan chip, I see.

https://www.reddit.com/r/intel/comments/zpgy7j
 

gillmanjr

Member
A couple things here.

1. When you built it, did you make sure to use the standoffs between motherboard and case if case requires them? You could be shorting out somewhere causing the problem. Also make sure that there are no metal tabs from the I/O plate sticking into the network port.

2. Are you running the latest bios version? which is 7D91VH2

3. Go here and use the Intel support assistant to see if there is an updated driver for the ethernet port. https://www.intel.com/content/www/us/en/support/intel-driver-support-assistant.html

They are having problems with that lan chip, I see.

1. YES. The port is clear and I don't think its a shorting issue.
2. I don't think so, no. I haven't checked because I don't want to go back into the BIOS but I doubt its the latest version. I really don't want to flash the BIOS unless I absolutely have to. And right now everything is working. If I start having the LAN port drop out on me while I'm actually using my PC (gaming or whatever), I will do that. But for now I'm leaving it as is.
3. The driver I have is the latest, I've already confirmed that.

Yes I've seen that there are issues, at this point I'm assuming this is due to those issues and is not an issue with hardware.

Luckily this is a relatively minor issue in the grand scheme of things because, number 1 my wifi works perfectly and number 2 I can always get an ethernet to USB adapter or a dedicated PCIe LAN port and use that, if it comes down to it. Using exclusively WIFI for a gaming PC is not something I'm willing to live with so if I have any other problems with the LAN port I will take additional action. I have no reason to go into the BIOS again, I have XMP enabled and my OC settings the way I want them. With my last build I don't think I ever reloaded the BIOS again in over 4 years of use once I had everything set the way I wanted it.
 

gillmanjr

Member
Ok so this is actually even more strange than I thought. So the LAN port will actually stop working even if just reset my PC. I don't even have to go into the BIOS. If I just do a normal reset, it doesn't work when the PC comes back on. The only way the LAN port will work is if I actually SHUT DOWN the PC fully and then power it back up with the power button on my case. And I haven't had any issues with it as long as my PC stays running. I'm wondering if this might have something to do with power savings options in windows 11. I actually haven't checked those. Really strange though.
 

gillmanjr

Member
I figured out what the issue was, I can't believe it. It was my UPS. Just an FYI if anybody out there has an ethernet problem. I had my ethernet cable running through my Tripp-Lite UPS protection ports. Just for the hell of it I decided to disconnect them and run the line straight from my router to the PC. Now it works without any issues at all. Unbelievable. :rolleyes:
 
Top