My computer won't recognize there is an Ethernet cable plugged in

[Erice1996]

I have a an Ethernet cable (that I have tested on my laptop so I know it works) plugged into my computer and the light blinks green in the back but it won't let me connect to the internet or even recognize a cable is plugged in. Any ideas on how to fix this?

 

[pavithra kannan]

goto device manager->network adapter->..double click on the " network adapter".. if there is already a" ethernet driver software" is installed then ..right click on it and "enable" it..or else "download" the driver software for ethernet cable ,which is also suitable for your computer.
hope diz will help u out

 

[Aaditto]

Hello nukemaster!

I am writing into this (old) thread since it is the ONLY one I have found - after hours of searching - which resembles my issue...
I am not even sure if this thread is still 'active'/ whether I should start my own thread!
But seeing your detailed responses encouraged me to give this a shot...

My issue: (well, the present one, anyway!)
[Unlike the original poster's problem, where Erice1996 reported that the computer "won't recognize there is an Ethernet cable plugged in"]
[But just as Erice1996 reports later,]
My Device Manager doesn't even show a Network tab.

[And also, as with Erice1996's issue]
My problem(s) seems to have developed ever since I upgraded to Windows 8.1 (Everything was fine while I was with Win XP!)

I have a 'home-built' Desktop Computer (I am not a geek, just someone who has to run a rural organisation in India where nothing is accessible and very little funds at hand - and also, someone who enjoys DIY'ing)

Specs:

• 
  ■ Motherboard:-
  Intel Desktop Board DG41WV - Essential Series - motherboard - micro ATX - LGA775 Socket - G41 (Here's a CNET link with the specs)
  ■ Onboard Gigabit Ethernet:-
  Integrated 10/100/1000 Network Connection
  (The onboard chip is too small to read clearly - i think it reads...) REALTEK RTL811DL
  ■ OS:-
  Windows 8.1 Single Language (English) 32-bit - Full Version (OEM)

There are OTHER errors that have been occurring lately - which were probably triggered by my rural-staff not shutting down the system properly, while I was away (they were constantly 'hard booting' to shut-down, with the power button, as they could not find the 'Shut-down' command as easily on the 8.1 interface!)...

I can give you a step-by-step of all that has been happening - but I am not sure whether that is required at this moment.
[The BIOS was not loading, to begin with... CMOS jumper re-set etc. did not help - three-beeps heard even before post - so, I searched and found that this was a RAM failure notice - opened and re-set the RAM... changed it's port... finally, a thorough rubbing of the RAM terminals, and violla, system was up and running!]

The basic issues at the moment are:-

• 
  ■ CMOS CHECKSUM ERROR
  Every time I power off and start the system again, POST shows CMOS checksum AND Battery failure error.
  However, the battery shows 3.02 V on a Digital multimeter - and the battery socket seems fine, at least from the top-view of the mobo.
  ■ Device Manager does not even record a Network adapters tab!!!
  (Even after I try connecting my modem/ laptop with the Rj46 cable)
  However, when I connect the same modem with the (optional) USB cable, the Network adapters tab appears - showing "USB IAD LAM Modem" details!
  At this point, if I choose to 'Show hidden devices', a long list of (mostly) 'unselected' items are displayed - but NONE OF THEM look like the one I need - for example, there's none from Realtek - though there are a number of 'WAN Miniport' items.

I have already tried a number of remedies (which I will gladly narrate, if you ask for it)...
Howerver, at this point I have a feeling that I need to first check whether the onboard LAN is shot, or is it a BIOS settings/ OS compatibility/ driver issue...

In your last note to the original question you had mentioned something about "trying a live CD/DVD of Linux"... Can you please help me to - (1) understand what you mean by that - (2) guide me through the process?

Or, do you think I should try something else??

Thanks in advance...
Cheers!

I do not have good news. The older(XP system, but it has an Nforce based chipset and realtek based network card) system I checked DOES show network cards in the same spot as my newer systems.

I almost have to wonder if some kind of hardware failure has happened with the onboard network card.

What do you see

If you felt adventurous, I would recommend trying a live CD/DVD of Linux. Live CD's do not install as long as you run them in live mode(they are not fast because they run off the cd/dvd, but they to work). They tend to have drivers for almost everything and at least if the network card worked on it, you would know it is a Windows issue and not a hardware failure issue.

 

[nukemaster]

A 2032 battery like in a computer may have a voltage drop under use that does not show up on a multi meter. If you can measure it while installed in the holder you may get a better idea.

Most bios on some boards will also allow you to see the battery voltage.

For the price it may be worth at least trying a new battery.

As for the try a live CD/DVD

A live CD/DVD is just an operating system that runs from a CD or DVD. Because of this it can not have any changes made to it, but it also somewhat slow. I reason I suggest this is just to see if Windows is the issue or the hardware it self. Many live versions of software can now run from a USB stick as well.

Setting it up is as easy as burning an ISO image.

With the disc burned you can just tell the bios to boot from that disc. In live mode it will NOT effect anything on the computer. These live discs have drivers for almost everything so that is why they are good for testing.

 

[Aaditto]

Thanks a tonne for your prompt response!

Will get back after I follow-up on your suggestions...
At the moment we are encountering massive power-outs, thanks to disturbances in the rural electrical-grid. So, I'll probably need a couple of days.

Cheers!

PS: One small clarification:-

While checking-out your suggestion of testing with a live CD/DVD of Ubuntu, I am finding more than one options...
[Like this page from 'ubuntuforum' lists TWO OPTIONS]...
<<
1. Run a live session booted from a CD/DVD/USB drive and select 'Try Ubuntu without installing'
a. Basic install drive (live drive)
b. Persistent live drive
>>

I am assuming that option "a. Basic install drive (live drive)" is what I need, right?

A 2032 battery like in a computer may have a voltage drop under use that does not show up on a multi meter. If you can measure it while installed in the holder you may get a better idea.

Most bios on some boards will also allow you to see the battery voltage.

For the price it may be worth at least trying a new battery.

As for the try a live CD/DVD

A live CD/DVD is just an operating system that runs from a CD or DVD. Because of this it can not have any changes made to it, but it also somewhat slow. I reason I suggest this is just to see if Windows is the issue or the hardware it self. Many live versions of software can now run from a USB stick as well.

Setting it up is as easy as burning an ISO image.

With the disc burned you can just tell the bios to boot from that disc. In live mode it will NOT effect anything on the computer. These live discs have drivers for almost everything so that is why they are good for testing.

 

[nukemaster]

I would recommend try without installing, but livedrive is an option I have not even looked into.

 

[Aaditto]

Hello again, nukemaster,

[I will get back to your suggestion of 'running Ubuntu without installing' in a while - I do need a bit of clarification in that too. But for now, there are certain other 'developments' which, I feel, might be particularly telltale ]...

To begin with, let me apologise - this is going to be a long one!

General observations:-

APPARENTLY, MY BIOS DOESN'T READ MY SYSTEM/ MOTHERBOARD AT ALL!!!

• 
  ■In the BIOS menu...
  Advanced> Hardware monitoring> (values are being displayed for) Processor thermal margin/ Motherboard temperature/ +5v, +3.3v, +12v/ Processor voltage etc...
  
  But, in the menu section...
  Main> Additional system information> System information/ Desktop Board/ Chassis Information sections ~ Manufacturer/ Product name/ Version etc ~ ALL SHOW *BLANKS*!
  (My MoBo seems to be an 'OEM version' - and I think I read in an Intel support page that 'third-party' modifications may exist in such boards)
  
  ■As soon as I turn on the UPS power, when the MoBo power-LED comes on, (before i hit the system power button) - both the signal lights above and below the LAN port come on - and stay fixed - one amber and one green.

developments:-

• 
  ■ After I re-set the CMOS jumper one 'last time'- this was probably the 6th time I was trying that to see if anything changes - and re-started the system, the CMOS checksum & battery failure errors have magically vanished!!
  
  I have powered-down and restarted a number of times after that - and still no error.
  
  The only difference I can think of, between my earlier attemps and this one, was that I had casually pinched down on the battery holder clip this time, just to check that it was tight enough.
  
  Incidentally, as per your suggestion, I checked in the BIOS settings, and yes, indeed, there was a section showing the (3.3V) battery voltage - and it was displaying as '3.236 V'.
  
  ■ I had tried to load the LAN drivers in the software CD provided with the Mobo earlier - but that had repeatedly failed - with the same issues reccuring everytime.
  
  Now I located my particular
  LAN (model) controller on the
  Realtek site - and found that there was a Windows 8/8.1 specific versions of the driver package - which I downloaded.
  
  But the exact same issues were repeated when I tried to run this new driver!
  
  What happens is this:-
  ■ The Realtek driver install window opens> 1st screen asks me whether I want to *Install/Repair/Remove* the driver (I have tried both Repair & Install, after Remove)> Install shield wizard starts the process, (the *Remove* works smoothly) copies 'updated files', with a top-note saying *...is repairing Realtek Ethernet Controller Driver*> then it begins to 'search for a Realtek Network controller'...
  
  ... AND, DAMN! A new pop-upopens - with the message *The Realtek Network Controller was not found. If Deep Sleep Mode is enabled Please Plug the Cable*
  
  [I have, of course, tried with the LAN cable (functional, tested with other system) jacked-in - with the same effect!]
  
  ■ A similar issue occurs if I try to run the MoBo software CD 'as-is' - that is, run the whole driver CD, and not just the LAN drivers...
  
  ~ If I let it 'auto-run', then the Intel Express Installer window starts, bot soon a new pop-up says *Current system is not an Intel(R) Desktop Board - (A044412A)*
  hen I click the 'ok' on that pop-up, the *Intel Express Installer* opens up - but the 'Install Sofware - Desktop Board' main-panel lists > Component> No component for this motherboard> Status> not installed.
  
  ~ I've tried running the *.exe as 'administrato' - same result!

BUT OTHER THAN NOT READING THE LAN, THE SYSTEM SEEMS TO BE WORKING FINE, FOR NOW!

Any suggestions as to what might be wrong?

Or should I just go with your original suggestion and try running Ubuntu? (The thing is, my net is super-down at the moment... but it'll give me a window at some point - that's when I plan to delve into Ubuntu!)

Thanks again...

I would recommend try without installing, but livedrive is an option I have not even looked into.

 

[nukemaster]

It depends on the board, One of my boards had a feature in the bios called green Ethernet or something like that and with it on, my network card would disappear unless it was connected to something.

Now this was more complicated because I have a Dlink green switch that shuts off ports when not connection is detected. Because both devices turned off and just sat waiting for another device switch them on, I had no network at all with the feature on.

Using my older non green switches also solve this issue, but thankfully, I could disable the feature in the bios.

The part about information to be filled by OEM is pretty common on many boards like that.

Does the card show up in the device manager? Hold start(winkey between alt and tab) then R on the keyboard. In the next window type devmgmt.msc and hit enter.

Look for your network adapter.

It should look something like this. Keep an eye out for yellow exclamation marks and stuff.

 

[Aaditto]

....
Does the card show up in the device manager? ...
It should look something like this. Keep an eye out for yellow exclamation marks and stuff.

Do you mean whether the LAN card shows up on the device manager?

No, it doesn't - that's the problem - from the start!

No yellow flags iether.

 

[nukemaster]

If you do not see Network adapters listed then you have more problems for sure.

Please ensure the bios does not have a green or other power savings feature for Ethernet(because those shut it off before the OS loads.).

 

[Aaditto]

Hi,
Thanks again for your inputs.
I can't locate any such 'switch' within the BIOS screens - there's only one option related to the LAN, apparently - that of 'enabling/disabling' it - and I have it enabled.

One thing that strikes me as a bit odd is that BOTH THE LAN-PORT SIGNAL LIGHTS come on - and stay on - as soon as I turn the power on - even before I actually switch on the computer. Is that NORMAL?

If you do not see Network adapters listed then you have more problems for sure.

Please ensure the bios does not have a green or other power savings feature for Ethernet(because those shut it off before the OS loads.).

 

[nukemaster]

Yes many boards do this.

Some computers allow you to power them on over the network(good for a business, but I have never used such a feature[I do not even use wake on lan]).

 

[John_136]

I have the same issue on one of our machines. It's a acer with Realtek driver. I can't even reinstall windows update as something has shafted that also. All checks say everything is working but the network simply doesn't show and there is no access.