Ethernet cable unplugged

I'm another victim. But I've found that the workaround posted in the discussions by goosewild is the solution that has gotten me going again...

goosewild wrote:
The only solution I have found is to manually set the Ethernet to 100baseTX.

OK, so this workaround limits me to 100mbps full-duplex flow controlled rather than 1gbps. And the one device on my subnet that speaks 1gbps is my NAS. But everything still goes fast enough for my needs, even my media functions.

Yeah, Apple's probably got a hard/firm/soft -ware bug somewhere in their system. But this is an immediate workaround for those of you who are out of warranty or who are on deadline.

- Sparky

I have the exact same problem. The network preference says cable is unplugged although the same cable works on my other laptop. I reset the PRAM, did the SMC, did a clean install of leopard. Ran the hardware test successfully. In the System Profiler I can see the ethernet card detected and given a MAC address and assigned the name en0. It also shows when I do ifconfig.

My macbook recently went a repair. Its internal charging card burnt down due to electrical surges so had to get it replaced and got a new MagSafe as well.

Its been over an year since I purchased my macbook but the online website says its under warranty till 21st August 2009. I had purchased it in April 2008 thats what is on my receipt. I had purchased it through a reseller.

Suggestions ?

I had exactly the same problem on my brand new MacBook Pro. I've only had it for a few hours and now it's back to the Apple Store I go.

The Ethernet Cable Unplugged error goes away when I manually set the speed to 10baseT. Definitely a hardware problem.

This is a sad state of affairs... just throwing my hat into the ring as well. 3-month old Macbook Pro 17" and after my upgrade to Snow Leopard, ethernet port won't connect at gig speeds. Link light on switch just blinks on and off slowly. Using a 100meg switch or hard-coding to 100baseT in settings gets a stable connection. Using another Macbook with same switch and cable works at gig speed without problems.

Based on this thread, it seems to have gone bad coincidental with my Snow Leopard upgrade, and here I thought it was a firmware issue. Guess not... Restoring the Leopard system and I have the same problem. 😟

I have a similar problem. with ethernet cable plugged into router (and Advanced > Ethernet > Configure = Automatically), my 1 yr-old MacBook cycles (sometimes rapidly) between Cable Unplugged and Connected (with a valid IP address). this behavior seems to coincide with recent upgrade to Snow Leopard (10.6.2). If I change configure to Manual w/ 10baseT (higher speeds didn't work), it will connect steadily to router but slower (~5Mb download)-- using www.speakeasy.net/speedtest/. if I connect MacBook directly to cable modem, it connects steadily and downloads at ~3x that speed (~14.5M) . since that ethernet connection works reliably, I thought there might be a problem with my router (DLink) and probably not with my ethernet port. however, my 8-year old Powerbook with Tiger, when connected via ethernet cable to the same router downloads at the higher speed (~14.5M).

so, I wonder if Snow Leopard has a problem with how it negotiates the speed setting, depending on whether a router or modem handle that differently. I can get by with wireless (and if I need to check or configure my router, I could always connect an ethernet cable and manually set to 10baseT; it was just easier to plug in my trusty old PowerBook to check/upgrade router firmware today). but it does bother me that I can't use an ethernet connection. maybe I will buy another router at a local store to test if a different router would work better (and if not, return it).

I could reproduce the problem by plugging my Vonage phone adapter (for VOIP) directly into the Dlink router; when I unplugged the adapter from router, the MacBook maintained its ethernet connection with no problem (or if I plugged the adapter into a wall outlet that goes thru a switch and then to the router, there was no problem either). I suspected the phone adapter & after several hours on phone w/ tech support, Vonage sent me a new phone adapter -- but, same problem. however, when I then replaced my router (now have a Netgear 150-N), the problem disappeared -- Vonage adapter can be plugged directly into router with no interference with Mac. even though I had upgraded to latest firmware, Dlink WBR-1310 router must have been the problem.

I was able to get ethernet working following saweyer's solution.

My son's MBP-15" (late 2008 model) was unable to be connected using ethernet. He is on Snow Leopard. No matter what we do, the MBP just does not recognise the cable being plugged in. The same cable can go into an earlier iMac with Snow Leopard, and that works ok.

I chose to manually configurate with 10bT, and the cable is recognised.

Not sure why this is the case though.

7 days past the one year birthdate of my MacBookPro, I'm suddenly seeing an ethernet cable unplugged message. Took the computer to the Apple Store and they have to replace the port... will they charge me even though there was no mention of pricing?

My Macbook Pro is about 7 months old and I cannot seem to get a wired connection to the Internet. My PCs seem to work ok, but all of a sudden the ethernet port stopped working on my MBP this afternoon. I've tried different ethernet cables, but nothing seems to work. In Network Preferences, Ethernet is "disconnected." As others have indicated on this forum, it looks like I need to bring it to the Apple store. Any other suggestions are welcome.

The "change speed" solution worked for me a couple times and now I cannot seem to change the speed anymore in advanced ethernet settings. When I switch to manual it reverts to automatic as soon as I leave even though I save changes. i had one configuration with manual already selected but the speed box is blank and will not let me change it. Any help would be greatly appreciated.

Exactly the same issue. Have been using ethernet to sync to my Time Machine for years. Suddenly Ethernet port responds with 'Cable Unplugged". All the solution mentioned above (reset PRAM, remove then add ethernet from list, set to lower speed) don't seem to work.

Boris Veldhuijzen van Zanten wrote:
Exactly the same issue.

Welcome to the forums, Boris, but give us some more detail if you want help with your own version of "exactly the same" issue.

What model of MBP do you have? When you say "Time Machine" do you really mean a "Time Capsule" or are you talking about a third party network drive using Time Machine software, or something else? ? Is whatever it may be connected directly by cable or through a network hub, switch or router or other device? What else is on the same network? Have you tried restarting the external drive or Time Capsule (whichever it may be) ? Does anything else access the same device? Have you tried a new cable? If it is really a "Time Capsule" have you tried using wireless? If it is simply a network drive what brand is it and what type of ethernet port does it have? Or is it a USB drive hooked up through an Airport extreme or other routing device through USB?

It is usually better to start a new thread and provide as much detail as possible when you run into an issue like this. There are a variety of different possible causes of ethernet problems, ranging through simple set-up issues to software and hardware problems, and even more possibilities if a network based backup device is involved.

One thing that I learned a long, long time ago here is that when people say they have the "exact same problem" they usually don't!

Without adequate information about their own situation it usually proves almost impossible to help them, as you can see from the variety of very vague "me too" posts in this thread spread over nearly a year and a half.

"Me too" posts are almost always a waste of everyone's time, I'm afraid. Given the number of variables they rarely provide enough information to let others help people resolve the issue, and, for the same reason, they make it next to impossible to sort out the "wheat from the chaff" when it comes to developing any idea of the prevalence of any particular real problem. Far better to start your own thread and post enough information to let others at least try to work on what your own particular problem is.

Cheers

Rod

justdoesnt wrote:
The "change speed" solution worked for me a couple times and now I cannot seem to change the speed anymore in advanced ethernet settings. When I switch to manual it reverts to automatic as soon as I leave even though I save changes. i had one configuration with manual already selected but the speed box is blank and will not let me change it. Any help would be greatly appreciated.

It is completely impossible to even begin to answer your question or offer any help at all until you provide more information about what you are connecting from and to, and how, justdoesn't.

Start a new thread with at least the basic information and I'm sure someone will try to help you out.

Rod

Indeed there must be a problem with the new version of software or hardware. My brand new Macbook Pro has the same exact problem. However, mine works in some networks, but not all. I took it to a apple store and they tried 5 different cables and all worked, so they didn't do anything. Anyway, the solution of manually changing the ethernet setting to 100BaseTX worked for me.
Thanks

Here's a summary my recent experience with this problem.

Gave a user a new Unibody MacBook Pro. In his office I couldn't get an ethernet link.

His old MacBook Pro, my own, and another all worked perfectly when plugged into the ethernet in his office.

The new Unibody's ethernet would work fine in different offices.

I could get the new Unibody to work in the user's office by manually setting the speed to 100BaseTX. I could also get it to work if I changed the speed on that port of the switch to 100BaseTX and set the Unibody to Automatic. But this user needs gigabit.

So I called in someone to check the wiring. Sure enough the cable was damaged near the punch-down block. There was enough slack to cut out the bad part of the cable and the problem was solved.

Why the only device that was impaired by this damaged cable was the Unibody MacBook Pro, I don't know.

Bizarre stuff.