iMAC 21" WIFI failing after 10.7.4 update

ok folks, posting seemed to jinx it

same problem. Lost wifi (while working). Needed to reboot to see SSIDs

back to Apple

will keep checking here to see if anyone comes up with a fix (that doesn't require killing bluetooth)

cheers

Guy

Problem got back! :-(

I hope Apple fix that soon!

Same here. When wifi is getting lost, i am getting lots of these entries in log:

kernel: 5702.261972: ath_chan_set: unable to reset channel 5 (2432Mhz) flags 0x10080 hal status 17

Hi All,

Experienced the exact same problem when I upgraded my iMac 2011 from Lion 10.7.2 to 10.7.3 - Wi-Fi dropping every half an hour and not reconnecting when returning from sleep.

After endless hours of frustration I ended up with a solution suggested in this thread:

https://discussions.apple.com/thread/3704573?start=104&tstart=0

In a nut shell, seems like there's a problem with Atheros based cards when used in conjunction with bluetooth peripherals (at least that's the leading guess 😕).

The solution works as follows:

1. Get the "IO80211Family.kext" file from a time machine backup of 10.7.2 (File found in /System/Library/Extension). Would have shared mine but not so sure it's legal...

2. Download the Kext Utility found here: http://cvad-mac.narod2.ru/Kext_Utility/Kext_Utility.app.v2.5.1.zip

3. Drop your restored kext onto the app and let it do it's magic.

Funny enough, the problem returned once I upgraded to 10.7.4.

I've reapplied the solution once again and everything is back to normal.

If any of you will find this solution helpful I've done my good deed for today 🙂

Roi

my problem has been solved. it was really simple, i just set the WPA mode to "WPA2 Only" on my D-Link router. It was set to "Automatic (WPA or WPA2)". the reason I did that because I realize all the visible SSID from my neighbours are using WPA2 only. I am not sure whether it works for you guys, but you can give it a try.

Same problem here. iMac 27 mid 2011. The Mac does not see neighbours networks either. All other devices like ipads and phones are working. Extremely frustrating.

Wow, feels like i am using a hackintosh - but wait, i bought a real Mac!

Same problem here with a 27" 2011 with 10.7.4.

I have tried to change wifi setup and disable timemachine, but the problem steel intact. 😠

Hello,

I am a Belgian guy with an iMac 21" 2011 and my father has an iMac 27" 2011. We both installed the 10.7.4 update this week. Since than we have the same problems as everyone else in here. The wifi fails all the time and our Macs can't see any network.

I am not pleased with this because I need the internet a lot for school these days. I hope that Apple fixes this as soon as possible.

Grtz from Brussels

I have been having WiFi Issues ever since upgrading to Lion. I tried numerous things with AppleCare, with forums, etc. Some "fixes", EFI update, etc seem to work for a day or two. .. then back to dropped connections.

The 10.7.4 update actually made it worse than ever. I'm surprised I didn't lose my connection while typing in this forum. I can be typing an e-mail and bam.. dropped connection. At least I don't always have to restart.. just turn WiFi on and off usually helps to get a connection for a few more minutes.

Disabling bluetooth is NOT a reasonable option. My Apple Keyboard and my Magic Mouse are bluetooth.

It's not the router. I have Airport extreme and my macbook, iPad, AppleTV, and iPhone keep their connections beautifully.

🙂 Possible (and temporary) solution found by JoiTal! 🙂

Inspired by the previous post by JoiTal about restoring a previous verion of the "IO80211Family.kext" file, I decided to try it out, and it seems to work!

Naturally, Apple needs to fix this anyway. And... please, do a backup of your system, before you re-install the old kext file.

I have the exactly same problem!!

I'm not having the exact same symptoms, but my wifi is dropping connections since applying 10.7.4. I can usually fix it (temporarily) by turning off wifi and then back on again, though it usually comes back again until I do a restart. Not sure if it only happens after waking up from sleep mode, but it's likely.

The problem seems to occur when streaming video. An HD YouTube video could trigger it, or a livestream. Maybe it's a problem with longer bursts of data from a single source. Could also explain problems people have with Time Machine.

I have a 2011 21" iMac with a Ubee wifi-router. Not using Airport or Time Machine.

First check for wireless channel interference around your wireless router by using a the free iStumbler. This way you can see if another wireless point is interfering with your wireless router channel. This could cause the wireless dropouts you are seeing.