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Lost Ethernet port - 2018 Mac Mini

B

brentsg

macrumors 68040
Original poster
Oct 15, 2008
3,587
943
I have the 10GbE port on my 2018 Mac Mini. Yesterday I upgraded to a major new release on my NAS and it required me to rework my Mac's network shares.

During a reboot on the Mac, I noticed the port on my switch flashing red. Yup, "no cable attached" warning in network settings.

So far:
  1. Unplug/replug cable
  2. Power cycle Mac
  3. Toggle Ethernet on/off
  4. Tried a different switch port
  5. Tried a different cable
  6. Performed a PRAM reset
  7. Power cycled the switch
Anything I'm missing? It seems wild that I'd just lose the port on a regular reboot. Now I'm on a Thunderbolt to Ethernet adapter, but at 1GbE, so it'll suck moving large files.
 
What macOS are you running? Any beta software? Remove the Ethernet port in Settings and re-add if you have not already done so.

As it seems you have already performed the PRAM reset, try resetting the SMC as well. Strange issue to pop up all of a sudden.
 
macbookm1airlover said:
What macOS are you running? Any beta software? Remove the Ethernet port in Settings and re-add if you have not already done so.

As it seems you have already performed the PRAM reset, try resetting the SMC as well. Strange issue to pop up all of a sudden.
Click to expand...

Big Sur, updated. No beta software.

I removed the Ethernet port in settings and now when I try to re-add, Ethernet is not one of the choices. I'll look into SMC. When I run a system report, the physical port isn't listed under Ethernet.

Agreed this is a strange thing.
 
Is there another network or router to which you could take the Mini and connect it there?
The idea is to try it in a completely different situation/setup and see if the problem re-occurs...
 
Fishrrman said:
Is there another network or router to which you could take the Mini and connect it there?
The idea is to try it in a completely different situation/setup and see if the problem re-occurs...
Click to expand...

At this point I removed the ethernet port in settings and cannot add it back, so I'm screwed unless I reinstall OSX I think.
 
Might be time for a visit to the nearest brick-n-mortar Apple Store...
 
iMacDragon said:
It could well just be a dead ethernet port, I had that happen on an old Mini.
Click to expand...
It's my guess at this point, but would be nice if the hardware check would flag this.

Seems so strange HOW it happened, which was basically me rebooting as I changed mapped network drives. I usually associate lost ports with physical activity and/or an electrical vulnerability but none in play here. Everything is properly isolated and the Mini probably hasn't had Ethernet plugged/unplugged 4-5 times in 3 years.
 
Once more... take it to a brick n mortar Apple Store.
They ought to be able to tell you within a few minutes as to whether the ethernet port is ok ... or not.
 
Fishrrman said:
Once more... take it to a brick n mortar Apple Store.
They ought to be able to tell you within a few minutes as to whether the ethernet port is ok ... or not.
Click to expand...
I get that. Unfortunately it's a few minutes, plus a couple of hours driving and whatever time they place me in a queue.

We don't all have Apple stores around the corner and it's not worth the time. I'll use it with a USB-C adapter until such time I replace it. Maybe some day I'll try a fresh OS install, as I have some other issues with the device at a software level. I definitely wouldn't buy a new logic board anyways.
 
@brentsg I am having the same issue. 2018 Mac Mini 10Gbe port. Was working fine, but just stopped earlier this week. I did upgrade to OSX 11.6, but I *think* it worked after that, not 100% sure.

Anyhow, I have tried PRAM resets, etc. Apple Hardware Diagnostics shows no problems, etc. Sounds exactly like your problem. I read "delete the Ethernet connection" but I went to add a new one first - good thing because the option for Ethernet is not there.

I can see in System Report that the adapter is still showing. I go into terminal and use ifconfig and I can see the connection:

en6: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
ether ac:de:48:00:XX:YY
inet6 fe80::xxxx:48ff:yyyy:zzzz%en6 prefixlen 64 scopeid 0x4
nd6 options=201<PERFORMNUD,DAD>
media: autoselect (100baseTX <full-duplex>)
status: active

I have a hunch it isn't dead, but I have yet to find the magic to make it work. I have confirmed it is not the existing cable, by plugging that into a laptop. I have also confirmed it is not a dead port on the router.

Beats me what it is, but I think it is a larger problem from Apple.
 
When adapters stop working like this, so they still apparently show working to the OS it's probably the PHY chip that's busted, that goes between the logic and the cable.
 
iMacDragon said:
When adapters stop working like this, so they still apparently show working to the OS it's probably the PHY chip that's busted, that goes between the logic and the cable.
Click to expand...
If the PHY chip is the problem, why would the linux system report it as working and the GUI not see it? System Report shows the card is present and ifconfig shows it has an active connection. I think this is why Apple Hardware Diagnostics also show no problem - because the chip seems to be active to parts of the kernel/OS.

Is there a way to ping it or any diagnostic to prove the PHY is what is broken?
 
Hate seeing this post, because I too have an 2018 MacMini i7 with 10GBe and poof, ethernet port just disappeared 3 days ago, Nov 28th. 2021 while running the latest of Mojave. Fearing it was some virus or low lever firmware intrusion, I just did 3 complete fresh upgrade installs from External USB drives and erasing Internal SSD each time of: Catalina, then Big Sur, then Monterey. None of the installs saw an Ethernet Port (Wifii & Thunderbolt 1,2,3,4, & Thunderbolt Bridge). (Also BlueTooth but that went away in Monterey.). I have an appointment at the Apple Store in an hour and will let you know what happens.
 
Doug183 said:
Hate seeing this post, because I too have an 2018 MacMini i7 with 10GBe and poof, ethernet port just disappeared 3 days ago, Nov 28th. 2021 while running the latest of Mojave. Fearing it was some virus or low lever firmware intrusion, I just did 3 complete fresh upgrade installs from External USB drives and erasing Internal SSD each time of: Catalina, then Big Sur, then Monterey. None of the installs saw an Ethernet Port (Wifii & Thunderbolt 1,2,3,4, & Thunderbolt Bridge). (Also BlueTooth but that went away in Monterey.). I have an appointment at the Apple Store in an hour and will let you know what happens.
Click to expand...
Please let me know what you learn! I think there is likely a problem with manufacturing/design. I don't think it is software related, though I'd love to be wrong about that. If I had to guess, it would be heat related. What doesn't make sense, though, is that the BIOS seems to see the chip, but the GUI doesn't. I can't get it to work no matter what, though. I went and bought a USB-C to Gigabit adapter, which works fine, but I miss my 10G connection.
 
I took it to an AppleStore and they are going to replace the motherboard. $480. Stinks but cheaper than buying a new one and I still get to have 4 TB ports. Anyway i will see if I can open a ticket at Apple about this ‘flaw’ because hard to believe 3 of us lost the same port within a month of each other. Can I get your information so I can forward onto Apple. Can we PM here?
 
Doug wrote:
"I took it to an AppleStore and they are going to replace the motherboard. $480. Stinks but cheaper than buying a new one and I still get to have 4 TB ports"

Don't do that.
Instead, buy a cheap USB-to-ethernet connector -- probably $25 or less.

You will have to do a little research to determine which one works with the Mac (check user reviews).
You will lose a USB port.
You will be "back down" to 1gb ethernet.
BUT... you will SAVE almost $500.

That works for me.
 
Last edited:
Fishrrman said:
Doug wrote:
"I took it to an AppleStore and they are going to replace the motherboard. $480. Stinks but cheaper than buying a new one and I still get to have 4 TB ports"

Don't do that.
Instead, buy a cheap USB-to-ethernet connector -- probably $25 or less.

You will have to do a little research to determine which one works with the Mac (check user reviews).
You will lose a USB port.
You will be "back down" to 1gb ethernet.
BUT... you will SAVE almost $500.

That works for me.
Click to expand...
That is what I did too. I’ll just use it to perform the odd job my Windows box with proper Intel NIC can’t do. Probably my last Mac unless work keeps buying my MacBooks.

I’m fine with sharing info if someone PM’s me.
 
I think the problem is heat-related. Try looking at other 10Gb Ethernet adapters, be it a Thunderbolt-to-Ethernet adapter or a PCIe card. Most of them have quite a big heat sink, some are even equipped with a fan or two. So there is a good chance the problem will happen again with the new logic board.
 
Ok, got mine back from the Genius Bar. Not cheap ($448 plus tax for $484), but I am opening up a thread at Apple and hopefully enough people report the same problem. (The external solutions are fine, but I think Apple should cover this issue.) So here is the discussion group at Apple, and please post there if your Mac mini has the same 10Gbe port dying issue. Lets get them to fix it. Thanks.

10Gb port on 2018 Mac mini disappeared - Apple Community

discussions.apple.com discussions.apple.com
 
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