1 2 Previous Next 15 Replies Latest reply: Aug 19, 2013 1:18 AM by SleeveMonkey
Mr G Almighty Level 1 Level 1 (0 points)

Hey all,


I've been having this problem for a few days now and it's becoming more and more frequent so now I'm really struggling to find help anywhere.


Basically after a while for no apparent reason my WiFi will stop working with the error message "DNS Server not responding" or something like that, and all my internet activity ceases. Turning off and turning back on the WiFi solves the problem temporarily but doesn't fix it completly. I'm using a Belkin N+ Wireless Router and a Virgin Superhub in Modem mode.


When my internet connection drops I cannot ping my router and I cannot ping google.com.


Here's what I have tried so far:

Renew DHCP Lease

Rebooting Router

SMC Reset

Rebooting computer

Virus Scan (Don't ask why)

Uninstall Hamachi

Replace Mackeeper with Avast

Software Updates

Jigging the network settings (proper service list order, adding a new location all that stuff)


A couple of ideas I'd like to try but I'm not sure about:

Changing the DNS on my iMac

Changing the DNS on my router

Seeing if the connection works on my Bootcamp partition.


That's really everything I know, I know that when this happens no-one else on the network experiences any problem at all. Up until this started happening this had never happened before, I hadn't installed any new software and I didn't do any updates when this started happening everything installed and uninstalled happened after this started happening


This is really frustrating and it's making my work alot harder any help would be appreciated



- Mr G

iMac (21.5-inch Mid 2011), OS X Mountain Lion (10.8.3)
  • 1. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Mr G Almighty Level 1 Level 1 (0 points)

    Further information:


    Google chrome gives this error message when the Wifi drops


    Error 105 (net::ERR_NAME_NOT_RESOLVED): Unable to resolve the server's DNS address


    And also when I boot up, Avast tells me of an internal error and I should check the avast program or the system logs, but I don't know where to find the system logs, or what I'm looking for in them.


    Thanks again

      - Mr G

  • 2. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Ralph Landry1 Level 7 Level 7 (32,450 points)

    First problem is use of anything such as MacKeeper or Avast...there have been regular problems reported on here with that kind of software...and MacKeeper is very hard to remove, it places files in hidden locations that are not removed by the uninstaller.  You need to thoroughly cleanse the system of MacKeeper and Avast.


    Second, when you say you did a router reboot did you disconnect the power to the router?  The DHCP daemon has to completely stop and many routers do not power down on the power button but go to standby.  The DHCP daemon does not restart properly under those conditions.


    Power down all devices and disconnect power to the router.  Wait ten minutes or so and then restart the router and give it a few minutes to capture the initial IP address and stabilize.  Then startup the connected devices one at a time giving each a few minutes to establish their IP address and stabilize.

  • 3. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Mr G Almighty Level 1 Level 1 (0 points)

    When I powered down the router I did disconnect it but only for a few seconds, and since finding out where the system log is I've seen a "daemon" section with a stream of information on internet activity, but when it goes down it stops.


    I'll unplug the router for about 10mins now, and do you have any suggestions on how to remove avast and mackeeper?



    - Mr G

  • 4. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Ralph Landry1 Level 7 Level 7 (32,450 points)

    Take a look at Klaus's user tip on MacKeeper, he refers to the sure way to remove it once installed.

  • 5. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Mr G Almighty Level 1 Level 1 (0 points)

    Phew, lucky me I used that exact guide to uninstall my Mackeeper.


    I've reset my router, and by that I mean leaving it off for 10mins and now I've connected back to it, is there anything else I should do?

  • 6. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Ralph Landry1 Level 7 Level 7 (32,450 points)

    Off hand for now just see if the system is stable.


    Have you checked to see if there are firmware up dates for the router?  You need to login to the router to do that, but that is all that comes to mind right now.


    Good that you did Phil's MacKeeper cleanup, should be ok in that area.

  • 7. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Mr G Almighty Level 1 Level 1 (0 points)

    I've unstalled Avast now, and mackeeper and while my internet is much faster the problem still persists.


    I've noticed I'm on channel 6, would channel 11 be better?


    It is last alot longer now but still happening every now and then

  • 8. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Ralph Landry1 Level 7 Level 7 (32,450 points)

    There have been other users who found moving to a higher channel helped their stability issues so give Channel 11 a try.

  • 9. Re: 2012 iMac OS 10.8.3 Wifi dropping
    sekiisaac Level 1 Level 1 (0 points)

    I'm having the same problem, and i think it all started when i updated to 10.8.3.  This happened to me last year on my imac and it was so annoying. it seems like everytime apple releases a new update there are bugs that cause my wifi to drop.

  • 10. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Helpstonharv Level 1 Level 1 (40 points)

    I have had this problem for months and have been forced to use an ethernet cable until this week when I have resolved my problem. I change the channel on my router from auto to manual and set it on 9 and applied it. Since then no problems. I believe it was interference from my house phone system so by changing the channel to 2 nopw operate on difference frequencies.


    hope you get it fixed

  • 11. Re: 2012 iMac OS 10.8.3 Wifi dropping
    dreve Level 1 Level 1 (0 points)

    I have the same problem

    After the 10.8.3 update, my modem wi-fi network has stopped working for me. I tried diagnostics but 2 wi-fi channel still doesn't work.

    I need to plug in a router (I use with hotel travelling for ethernet sharing) and that works

    Mobile broadband and tethering also works


    so it is very specific to which wi-fi connection the laptop will work now


    Tried everything as the original poster said, nothing works, I really need this working again

  • 12. Re: 2012 iMac OS 10.8.3 Wifi dropping
    iankh Level 1 Level 1 (0 points)

    I have the same problem. My iMac is on 10.8.3 and it disconnects from wifi after sleep. I have to search for my network and reconnect. I have an Airport Extreme.


    I've had both the Airport Extreme the iMac for quite a while This only started to occur with the latest OS X update to 10.8.3

  • 13. Re: 2012 iMac OS 10.8.3 Wifi dropping
    ssls6 Level 4 Level 4 (2,715 points)

    I hate to say this but your router "Belkin N+ Wireless Router" is not dual band.  When you have a mixed network of B, G, & N (like an iphone, mac, other stuff), your router switches bands leaving some of your stuff confused.  It happens more than you think.


    Try setting your router to B/G only and see if this fixes the problem.  If it does then you know what you need to do.  Get a decent dual band router.  I think the AEBS (airport extreme base station) is outstanding.

  • 14. Re: 2012 iMac OS 10.8.3 Wifi dropping
    Nbod702 Level 1 Level 1 (25 points)

    Mr. G,


    I have been having this problem with just one of our iMacs in our house.  I went through Apple support and navigated through all the twists and turns they suggested to try to get the problem solved.  NOTHING WORKED.  THEY DON"T KNOW HOW TO FIX THIS PROBLEM.  BUT I DO!  Unfortunately it involves buying a $30 wireless ethernet adapter (I got an IOGEAR, and I have no connection to their company.  Probably any wireless ethernet adapter will work).  I turned off the internal airport wireless device and through the network settings in the system preferences connected to my CISCO LYNKSYS ROUTER (which has been bashed left and right in the forums here).  THE PROBLEM IS SOLVED!!!!!   NO RESTARTING!!!  NO DROPPED CONNECTIONS!!!!


    So the problem isn't with the router, its with the airport wireless adapter in the iMac.  It ***** to have to spend more money after you lay out so much for an apple product, but it sure beats restarting the computer over and over every day.


    Hope this helps my friends out there.  I can now allow my hair to repopulate my head since I've been pulling it out over this issue for months.

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