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iMac 12,2 (mid 2011) airport (wireless) problem

I bought this week an iMac Mid 2011.

I have done every update from " software update", but i have an issue with the wireless connection.

Sometime the wi-fi connection freezes and internet doesn't work (ping with router fails). To solve I have to disconnect airport and re-connect.

The router wireless works (i have 4 pc + 2 mac + iphone, and i have this problem only with this iMac). In windows (bootcamp) wireless works fine.

Yesterday, when i opened Network Utility, opening the airport interface (en1) I had a kernel panic (this happened 2-3 times). So I reinstalled MacOsX.

Today I have the same issue with the wi-fi, but when i open network utility i have not kernel panic.


Someone has this problem?!


Solutions? Next week I'll call apple support to see if this is a known problem

iMac, Mac OS X (10.6.7)

Posted on May 7, 2011 5:35 AM

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Question marked as Top-ranking reply

Posted on May 7, 2011 6:58 AM

You can call AppleCare today, they're open in the US on Saturdays however because you don't state where you're located I can't vouch for your country.


You can try some fundamentals such as repairing Disk Permissions in Disk Utility, resetting the SMC and resetting the PRAM.


It also could be a simple issue with the DNS settings your ISP is using. Macs can be sensitive to these, if you are not familiar with DNS setting please read MacWorlds DNS Troubleshooting article and then make the follow change:


1. System preferences

2. Network

3. Click Advanced

4. Click DNS tab

5. Click + sign

6. Add 208.67.222.222

7. Click + sign

8. Add 208.67.220.220

9. Click OK.

10. Exit System Preferences

11. Try out your iMac and report what happened.


Roger

417 replies

Jul 7, 2011 6:05 AM in response to FloGo0210

I know you intended to be kind with your comment and not trying to start a flame war; but I think this is the perfect forum to point out when Apple is not living up to their reputation and obligation to create and deliver quality products. Because we all pay a significant premium to own their products we expect more from them in terms of responsiveness and service. In this case Apple is failing miserably in addressing and dealing with a significant problem.


Please don't take this comment as starting some thread crapping, just pointing this out.


Peace.

Jul 7, 2011 6:25 AM in response to sander81

I've had my new iMac 21.5 for about 3 weeks. Periodically, about 3-4 times a day, it loses its internet connection. What is indicated if toggling the Airport off and then back on always restores my connection?


I have cable internet and a Netgear wireless router. I also have a 1.5-year old Macbook Pro that does not have this connectivity problem (on the same network).

Jul 9, 2011 3:00 AM in response to sander81

I've got timeout problems with osx on my mac over wifi after 10 mins and I found this trick around.


I don't know it it could help but try these command lines (it's not permanent and it reset after a restart).


Terminal:

sudo sysctl -w net.inet.tcp.rfc1323=0

sudo sysctl -w net.inet.tcp.recvspace=32768

sudo sysctl -w net.inet.tcp.sendspace=32768

sudo sysctl -w net.inet.tcp.win_scale_factor=1

sudo sysctl -w net.inet.tcp.sockthreshold=0

Jul 13, 2011 2:05 AM in response to DamenS

Hi DamenS,


I dodn't know the type of router you are using but in my case turning off the option to use 300 MBit channels did the trick. Since then I havn't got the faintest drop out problems anymore (for two weeks right now). The downside is that you can't use 300 MBit...


Give it a try if you your router offers the option!


Regards

Christian

Jul 13, 2011 10:30 PM in response to Kricki

Well I have been having the same dropout problems as well as problems with the wifi connection after sleep. I run a 2nd gen airport extreme router WPA2 personal and both old and new iMacs as wells as MBPs on the network. The new mid 2011 iMac was the only computer having the problems previously reported. I tried every suggestion so far with no results (changing WPA to WEP, no security) Changing frequencies 2.4 and 5.0, clearing out keychain passwords for network, repairing disc permissions, and on and on. Finally, and it makes no sense I set my Airport extreme to only broadcast in g, Airport Utility->manual setup->Wireless->and option clicking the radio mode to get option for wireless g only broadcast. Drop out has stopped for a few hours so far and the no connection after sleep is no longer occuring. Time will tell. It is aggravating the new machine is performing so poorly, but hopefully the fix holds....

Jul 14, 2011 8:02 AM in response to sander81

Does anybody know whether the reported WLAN connectivity problems of the mid 2011 iMac and/or the early 2011 MBP still occur in combination with the 5th gen AirPoirt Extreme released end of June?


Many of us seem to have WLAN connectivity issues with various non-Apple routers, others - like LOtang - face the same trouble even with AirPort Extreme/Express routers of the pre-5th gen. Therefor I wonder whether the bug still appears in combination with the new APE which enables 450 MBit transmission - as the new MBP and iMac do.

Jul 18, 2011 6:22 PM in response to sander81

I have the same symptoms on my iMac 27" (mid 2011), all other wireless devices work fine with the router I use. I had initial good results today after manually changing the channel on my wireless router (I picked a random channel number), it was previously set to Auto. I was able to continuously stream a Netflix movie without stalling for over ten minutes. Previously it remained connected for only a few minutes before every network app on the iMac froze up. I'll know better results tonight but you may be able to fix this from your router. There may be many other wireless networks in your area that are using the same channel; changing the channel may help. Good luck.

Jul 19, 2011 4:32 AM in response to Simulator

According to my experience manually changing the channel does not lead to a sustainable bug fix but provides a stable connection for some days. Don't ask me why but the same effect applies for other sorts of resets.


The only sustainable fixes I heard about are to disable 300MBit (or comparable) optimization options in some routers or instead disable (or at least reduce) WiFi encryption.


And - for sure - there is still hope that Lion fixes the bug by providing adequate drivers...



<Edited by Host>

iMac 12,2 (mid 2011) airport (wireless) problem

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