Q: Update to Mountain Lion 10.8.5 has killed my wifi access. Help needed.

I have to admit that this issue with the late 2008 macbooks and macbook pros is exceedingly vexing and we have all spent many hours trying to find a way out only to be left disappointed. But overall with OS X over the years for me, this is by far the exception rather than the rule. Many updates are so seamless and you just keep working on barely noticing an update. And that's what makes the issue so frustrating for us all, we expect things to just work and for the most part that's the way it's always been. I too am hoping there is a fix in the works and we can erase this issue soon!

Interestingly enough, I have had no connection problems at home but have had wi-fi connection issues at work.  Not sure if this has been the case with you people. 

The steps that I took were the following:

1. Apple button > System Preferences > Network (made sure location was 'Automatic') > Advanced > TCP/IP > Renew DHCP Lease.

2. Lease renewed after several attempts (almost seemed as if the ip that was in there was 'stuck')

2a. All of a sudden, connected to wi-fi after numerous attempts.

3. Applications > Utilities > Disk Utility > Selected Boot Drive (Macintosh HD) > First Aid > Repair Disk Permissions

4. Restarted 4 or 5 times

5. Checked DNS under the steps in #1 (Network and Advanced) and DNS Servers had an address and the search domains had information in it (both before 

    were blank).

This has worked for me (for now).

Hi all,

I have a fix!

just got off the phone with tier 2 apple tech support.

I have a mackbook 2008 and when I upgraded to 10.8.5 my wifi was completely broken.

Went through all of the typical reset PRAM, remove battery...etc.

Here is the fix:

Go to network prefs

remove the existing wifi configuration

     select wifi

     select the - (minus sign) at the bottom left of the window.

Select Shut Down from the Apple menu.

Restart the computer.

Open Network prefs and select the + (Plus sign) at the bottom left of the window

For me, WIfi connection was populated already.

Select Create

Go to the menu bar and you should now see all of your typical networks displayed.

Select your network.

Waallla! Sanity restored and your Macbook is back in action.

Have a great day!!

Thanks for posting that.  I've seen it before in several other threads on this issue, only to have people come back to report it wasn't sustained.  Please let us know if it continues to work after several subsequent reboots.

Please let me know if your fix was permenant. Everything I have tried has not held up after a restart.

After taking my MB (Late 2008) to Apple Support at a nearby Apple Store, Genius Bar, they tried to fix and I had to leave with them so they can capture all the information from my MB to send on to their engineers.  It seems this is a known issue and they are working on it, or so they've told me.  I just hope they can fix this soon.

If you can get your hands on a 10.8.4 (OS X Lion), I would recomend you try this since some of you on this community have said this issue didn't exist on that version.  I'm going to call Apple Support and complain that if they can't tell me when they'll have this fixed they need to provide an interim fix (or ability to get 10.8.4 installed).  I would recommend you do same.

Good luck!

I think that all of us affected are hoping for a fix soon! It's good to know it's on Apple radar and they're looking into the issue.

On my searches of the boards, it seemed like this was a spotty issue previously with Mountain Lion before 10.8.5, but all the fixes we've already tried must have worked to alleviate the issue. With 10.8.5 the issue became much more widespread (on the late 2008 series of machines) and now none of the previous fixes worked on a consistent or permanent basis. At least there is 10.8.4 as an interim.

Thank you very much for this great advice. I tried out your first step and after it I removed my WiFi from my iMac. After it I restarted my Mac and I have my fast internet back after a week with very slow internet. With my iPad and iPhone my internet was always fast so I knew it is not a router problem. But after update to OS X 10.8.5. I had very slow internet with my mac.

Ok it's broken again. I did not use for half an hour and now it's same like before. Sometimes WLAN tells me that it has no IP Adress. And a minute later it's there again. I am not able to work with this slow internet. How is it possible to install back OS X 10.8.4 ? Without having a backup ? Just download from apple support ? And it overrides 10.8.5 version ?

I had a support call with Apple the other day where they ran my late 2008 MBP through a few troubleshooting procedures which fixed the problem temporarily until I restarted my macbook pro. Before the call I created a copy of the folder MacintoshHD/Library/Preferences/SystemConfiguration, and saved it on my desktop before deleting the entire folder. I then restarted my mac which brought WIFI back. From previous testing, I knew that the issue would return upon restarting.

During the support call with Apple, the Enginner made me rename the above folder to SystemConfiguration2 and then asked me to restart. After the first restart I had WIFI. On second restart no wifi. Her suggestion was to wipe the hard drive and start with a fresh install. I was not ready to do this yet so I told her I would do it later as a last resort.

After the call I needed to get WIFI back, so I deleted  all of the profiles in Network preferences and restarted.

After restarting I deleted the SystemConfiguration folder and System Configuration2 folders that was created during the support call and replaced it with the backup saved on my desktop. I then restarted my mac and wifi was still working. I  assumed that this fix was temporary and a restart would return the issue so I have not restarted my mac for the last 5 days. Today I tried my luck and restarted my mac to find it still connected to wifi. I have restarted and shut down over 7 times and it has connected every single time. I dont know how but mine has seemed to have fixed itself!!

Unfortunatley the WIFI issue has striked back. Ims so over it. Apple please fix this!!!!

Two workarounds for now.

After you have WIFI working do:

1. Always leave your computer in standby mode

or

2. Before shuting down, turn off WIFI. When you turn your computer on again WIFI will be off, but will work if you turn it on.

If you want a work around for staying with 10.8.5 (with or without updates), here's what's been working for me and until now (several shutdowns/restarts) continues to work.  I created three locations on my network preferences (e.g. None, Wired and Wireless).  Under my "None" location I have no network services defined, for "Wired" I have an Ethernet cable service, and for "Wireless" I have my WiFi service defined.  So here's how I do it, every time I'm about to shutdown or restart I go into my network preferences (choosing it from my top menu bar) and I choose my "None" location followed by shutdown or restart.  When back from shutdown or restart I go back to the network preferences and choose my "Wireless" location and apply.  This now turns on WiFi and assigns an IP, unless you're in a different hot spot (traveling) in which case you may need to choose a different WiFi network.

I hope this works for now until Apple figures out how to fix this annoying problem, but at least this keeps you from having to remove services, restarting, and adding back services.  The fact that this works tells me this is not a hardware issue as some at Apple Support are sometimes trying to indicate.

Good luck!

Thanks to all posters- the 8,9,and 10 step fixes had me filled with angst, I'm appreciating all of you who tried and posted which ones didn't work.  So far I think APPLE NEEDS TO FIX IT!!!! I waited a long time to upgrade to my nice little MacAir but it drops the wifi everywhere (tried 4 locations where all my other devices work just fine)

Hope is not a good corporate strategy to support customers!

Oh goody.

So now OS Mavericks drops my TC 5GHz network every 10 seconds or so.  That's impressive ...

Shall I start a new thread for that?