Q: iMAC 21" WIFI failing after 10.7.4 update

Lets remember that this isn't an Apple supported solution and whilst it does work it might cause issues during future upgrades so keep a backup.

Dom

Arya22 wrote:

 

This solved my wifi dropping problems:

 

http://www.appletips.nl/os-x-10-7-4-fix-voor-draadloos-netwerk-problemen-imac/

Just letting everyone know that replacing the kernel extension with the older (v. 4.1.2.) file also worked for me, as it has for many others. So far I've had three days (without reboots) and with no Wi-Fi problems.

Please bear in mind that if you do try this, you absolutely need to use program like Kext Drop. If you just manually replace the kernel extension file, there's a good chance you will only cause more problems.

I renewed my DHCP lease manually and it worked fine ---> now it wakes up and connects

- try to delete favourite connections also worked on some computer.

Thanks.  I just wanted to say that I was having the same issue after updating to 10.7.4 on my iMac.  Before updating I would have problems with wifi connections dropping.  My wifi setting gave me an error that said: "wifi had a self assigned ip address" with a yellow light.  I searched the net and tried many options and no luck. 

I tried the solution at this site mentioned above, followed it step by step and it fixed everything.

http://www.appletips.nl/os-x-10-7-4-fix-voor-draadloos-netwerk-problemen-imac/

I don't speak Dutch so I used a web translator to english to help me follow along easily. 

http://babelfish.yahoo.com/

Be sure to download the (v. 4.1.2.) kext file, download the software to properly install it and make a back up copy of the original kext file.  This solution was very helpful and simple. Hopefully it will work for you.

I am experiencing exactly the same problem on my mid 2011 iMac 27' after installing 10.7.4. Apple, please solve this problem ASAP!

I've done as described here, but to no avail, the problem persists, on my MacBook Pro Mid 2010 i7 model. I use Mac Os X 10.7.4

I recieved the same run around. I just bought the mac less than 30 days ago........should I return it.!!!!!!

Is this the kind of service I can expect from Apple. This is my first mac. I was all excited.......now I am feeling like windows 7 was a more viable option. I was able to see thru the smoke going up my xxx. I am willing to work with them....but I shouldnt have to go buy a new router because they speculate thats the problem. 4 other devices work perfectly fine. None my my other devices have " interference issues". Thanks for ignoring the obvious

I opened a case #. I suggest everyone that has the service plan due the same. They sent me a email asking my opinion. I have been reading up, thanks for everyones input. I will now reply to apples email.....good to know I am not in this boat alone as apple service was impling.

This is my 2nd iMac over the past 4 years having abandoned Windows because of the instability of the OS. Have also owned during this period two MacBooks.  The wifi drops are is the most difficult technical issue by far I've experienced with Apple.  Apple Care was somewhat helpful on the phone even acknowledging wifi connection issues with Lion.  Had my iMac in the Apple Store for 3 days.  They were unable to replicate the problem and reinstalled the OS.  That didn't help.  Staff did not acknowledge connection problems with Lion.

For the wifi drops I changed my router security from WPA to WPA+WPA2 as suggested in this forum.  This has stabilized things.  But I don't consider this a permanent fix.  Others have replaced the 10.7.4 1080211.kext file with an older version of that file.  You can search this forum for instructions if so inclined.

Lion itself is a downgrade from its predecessor.  Snow Leopard was a stable, sturdy, highly functional OS -- one of the best I've worked with.  In developing Lion Apple tinkered with everything, in many cases for no apparent reason other than to make it different.  It's really an OS without a good rationale unless you consider making a desktop and laptop look like a tablet a good rationale.  Overall a big disappointment

I have th same problem with an Imac 27, recently bougth and no solution yet.  Its  a SHAME for Apple. Why we don't start an activity on facebook against Apple, because I don't see any signs that these idiots are solving it.

Ill join a cause concerning this issue on fb. I did solve it with replacing a kext file ( all explained in a dutch apple forum I posted here), but now my iMac is not going automatically to sleep - only display does, the hard drive keeps working. Really frustrating! I am a switcher and I must admit that I Am really disappointed with so many issues in lion.

:(

Not sure if you tried setting your router to WPA2.  That change from WPA worked for a few of us.  I've been having no drops for 9 days now.

Almost as frustrating to me is the fact that the OS itself is nothing special -- a big disappointment actually and hardly worth the grief involved in this wifi mess.  Snow Leopard was a stable, sturdy, very functional OS.  In developing Lion, Apple tinkered with everything, in many cases for no apparent reason other than to make it different.  It's really an OS without a good rationale unless you consider that making a desktop and laptop look like a tablet is a good rationale. 

Hi All, I just wanted to post an update after replacing the .kext file.  So far so good and no sleep issues.  It's true every computer system has some glitches or issues but I really love Mac...it very easy to use, it's innovative and for the most part I do not have to troubleshoot constantly. 

It's great to have an online community to get support for your Mac.  If I do have any issues with my Mac which is not often...I simply google the error message and Volia!...I always seem to find the fix...And Hey it sure beats having to bring your PC into the shop for repair $$$$

MacLuvva

Hey guys,

just want to post my case / put more pressure on the subject.

I have a 2011 MBP 13" (March 2011), 10.7.4, German language.

I tried all fixes regarding changing encryption, tried everything in 3 different Wifis, tried deleting all passes and remebered Wifis, tried resetting SMC etc., added new locations in the network pane, tried a new user. Nothing worked.

I have the feeling that everything worked fine until a upgraded to 10.7.4.The drops don't seem to have a system. Sometimes 2 Min. after restarting, sometimes after 30 Min. Sometimes not for a day. I don't have Vmware or something similiar installed. tampering with bluetooth didn't help either. I also tried the "ping" suggestion and adding a DNS (8.8.8.8).

I had the feeling that old school encryption and lousy reception of wifi / poor internet connection does support quicker drop frequence.

My last hope is replacing the .kext file with the one from 10.7.3. Will try that later on.

Unfortunately I have not enabled TimeMachine. Can anyone advise where I could download the older version of the driver file?

There's a link on this site:

http://www.appletips.nl/os-x-10-7-4-fix-voor-draadloos-netwerk-problemen-imac/