Q: Mac mini says ethernet cable is not plugged in when it is

There likely is a console log file that should relate to the action or occurrence you

notice, in the time/minute/second the issue happens. This and other testing, may

lead to a good reason to consider professional diagnostic and perhaps repair if

there is some hardware ailment behind the problem.

Which Mini version do you have? Some that shipped with an older OS X then up-

graded to El Capitan, had graphic issues in Late 2012 build series; not sure if any

like that show up in newer hardware that uses newer graphics & other hardware.

Could be a problem that intermittently occurs; but log files may show events that

otherwise may not be detected until they reach a tipping point.

Not sure why the Ethernet should fail to work when booted in OS X 10.11.x yet

work adequately in a Windows OS. (windows users had said their mac was a

great machine for their os experience; I doubt this is what they meant though)

Hopefully you can find clues as to what is happening, or consider an appointment

with an Apple Store Genius (if available) or an Authorized Apple service provider

for diagnostic testing; and hopefully the issue can be resolved under AppleCare.

Good luck!

The Mac Mini build model you have is the current one, for the most part

the numbers change when there is an update in hardware, sometimes...

And there was a significant change between the Late 2012 models and

following Late 2014; the Late 2012 was in production & still available up

until the week or so (online availability varied from retail store) the 2014

model appeared. The Late 2012 were sought after by some; however a

top-end Late 2014 with max RAM and larger capacity SSD, with only

two core has a few noticable strengths, than the quad-core Late 2012 i7.

The graphic processors likely are a noticable upgrade in the 2014 build.

The now discontinued Late 2012 shipped stock with 5400-RPM HDDs.

A rotational hard drive could be seen as a bottleneck, at times. These

can be swapped-out with SSD or 7200-RPM HDD for performance gain.

Your model specs are current, according to http://mactracker.ca app

Introduced    October 2014

Discontinued    --

Model Identifier    Macmini7,1

Model Number    A1347

EMC    2840

Order Number    MGEM2LL/A (1.4 GHz), MGEN2LL/A (2.6 GHz), MGEQ2LL/A (2.8 GHz)

• Had you inquired of, or tried using, a Thunderbolt to Ethernet adapter MD463ZM/A ?

Apple Thunderbolt cables and adapters - Apple Support

There may be a hardware issue in the computer, however you may not be

able to detect the cause; and if sporadic or inconsistent, a pro may have a

harder time finding it since the problem has to show during the test. A few

tests can run a long time. Also, older cables or damaged ones can cause

problems; testing or troubleshooting would utilize known-good new cables.

Hopefully you can find and eliminate the cause of the problem. Can't say

much about windows seven, however with vintage correct hardware, the

Snow Leopard 10.6.8 is a durable and capable system; one of the best &

may be better than Tiger 10.4.11, in its best match (obsolete) hardware...

The computer should be tested by an authorized Apple technician while

there may be time; a hardware issue could be the cause of this problem.

Good luck in this matter!

Things to check.

• Try a different network socket
• Try a different network cable

As an example of where 'strange' things can happen, if you have a Gigabit capable network switch and your Mac is also Gigabit Ethernet capable but some or all of the cabling between your Mac and the switch is not Gigabit capable because either it is too old e.g. Cat3 or because only 4 of the wires are connected instead of all 8, then it might struggle to negotiate a connection.