Macbook Built-In Ethernet Appears to be Dead

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Level 1

20 points

Macbook Built-In Ethernet Appears to be Dead

I have 2 of the early Macbooks in our household. One of them I upgraded to Snow Leopard this week. Last Sunday the ethernet port seemed to work. After the OS upgrade (not a clean install w/ migration), the built-in ethernet port was not working. I had assumed that the failure was a side effect of the SL upgrade. I found a lot of articles describing the same problem, most of which called for deleting the /Library/Preferences/SystemConfiguration directory and all of the plist files within. I performed all of those steps and none of them got the built-in ethernet working.

The 2nd Macbook is still on Leopard, so I swapped the hard disk drives in both to see if the problem stayed with the 1st Macbook, or followed the SL installed HD to Macbook #2. The dead ethernet port stayed on Macbook #1. The ethernet port on Macbook #2, now running SL, works just fine.

In the 3 days between when the ethernet port in Macbook #1 was working to when it was not after the OS upgrade, there were no events that should have damaged the ethernet port. Actually the Mac was not use much at all over those 3 days. Although the symptoms strongly suggest that the ethernet port had died from hardware failure, I find it a little hard to believe.

Additionally I have executed the procedure for resetting PRAM and SMC.

PRAM Reset Procedure: http://manuals.info.apple.com/enUS/MacBook_Late2006UsersGuide.pdf
SMC Reset Procedure: http://support.apple.com/kb/HT3964

My question here is... Is there any way to reset the built in ethernet beyond what I have already done?

MacBook CoreDuo, 2 GB, Mac OS X (10.6.4), Windows XP w/ Parallels

Posted on Jun 18, 2010 11:59 AM

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Answer 1

Jun 18, 2010 12:25 PM in response to DParsons

Ports on computers go bad all the time. It's what keeps us repair techs in business. Cables go bad all the time, especially old IDE cables, CD/DVD drives go bad all the time, USB ports go bad all the time... Ethernet ports are usually a bit longer lived, but do still go bad.

So here's a simple test to find out if it's hardware or software. Turn the system so that the ethernet port is facing the edge of a table, or just figure out a way that you can get the port at eye level. Plug in a "live" and known good cable, and look for any flashing LEDs. Apple tries to conceal these by the case, but you can usually still see them if you look carefully. If you need to, get system #2 and look at it to give you some idea of what to look for.

If you don't see any lights, the port is absolutely dead. If you do see lights, it doesn't mean the port isn't dead, it just means that a tech will have a little additional troubleshooting to do.

The repair for this is to replace the logic board, and that will likely cost in the neighborhood of $500 if the unit is out of warranty. You may be able to find a motherboard from another system on ebay if you want to attempt this yourself. Make sure to find a couple of guides and review the process before you actually buy anything. Replacing a laptop logic board can be a pretty involved process.

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Answer 2

DParsons Author

Level 1

20 points

Jun 18, 2010 1:46 PM in response to Scott Billings

That turns out to not be as definitive as you might think. I had been using the Link light on the switch as an indicator, and I am using a known good Cat5e cable. Although it is good to know about the Link light on the Macbook, I have booted RJ-45s, and I think they are blocking my view of the obscured internal Link light. I am not seeing the light on the Macbook #2, but I have a good Link light on the switch.

As an example that shows that Link light does not guarantee that the ethernet port is dead, I can, for example, go into System Preferences > Network, and select "Make Service Inactive", and once I click on the "Apply" button, the system cuts power to the internal ethernet NIC, and the Link lights turn of (on both the computer and the switch). So that is ultimately under software control. If the light was on, that is a pretty definitive indication that the port works, but if it is off, it could be that the port is bad, or that it is not being turned on.

I do know that ports do go out, but am not yet convinced in this case. I would like to rule out more definitively the possibility that some issue is preventing the system from powering up the internal NIC. I have already priced out a replacement main logic board from iFixit.com. It is closer to $399 instead of from Apple for $500+. The system is old enough, I am more likely to just live without en0 until I get a new Mac. The system is already have intermittent problems with the inverter, which is an even bigger job.

Thanks though.

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Answer 3

yyckerr

Level 1

0 points

Aug 18, 2010 10:54 PM in response to DParsons

Dparsons I am having this exact problem and cannot wrap my head around it.

Apple! help.

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Answer 4

Aug 25, 2010 7:12 AM in response to yyckerr

My port seems to have dies as well. White MacBook. Few months old. Wish I had got a Windows laptop.

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Answer 5

bonald67

Level 1

0 points

Aug 27, 2010 8:00 AM in response to Rick Reed 10

My son is a freshman at Florida State, and he has to use a hardwired connection in his dorm room (routers not allowed). His connection worked fine for a couple days and then last weekend it stopped. He took the Macbook to the FSU computer store on Monday, where they also could not get it connected and sent it for repairs (it's under warranty). The guy at the repair facility had no problem at all connecting it and sent it back the next day. He plugged it in again in his dorm room and it worked . . . for about an hour.

We are still troubleshooting this issue, but I sent him a USB network adapter that I ordered off of Amazon for about 30 bucks. It arrived this morning, and it works! I am having him follow up with tech support on campus, because there is no excuse for him not being able to connect the traditional way.

Anyway, I just thought I would share, because it might NOT be a dead port. Hope this helps at least a little. Believe me, I know how frustrating this is.

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