HT202663: Use Wireless Diagnostics to help you resolve Wi-Fi issues on your Mac

Learn about Use Wireless Diagnostics to help you resolve Wi-Fi issues on your Mac
Briansaund
Level 1 (0 points)

Q: My iMac wifi does not work.  Diagnostics say that my router cannot access the internet but by Macbook Air works fine through the same router.  The Network Preferences pane says Wi-Fi does not have an IP address and cannot connect to the Internet.

My iMac wifi does not work.  Diagnostics say that my router cannot access the internet but my Macbook Air works fine wirelessly through the same router.  The Network Preferences pane says Wi-Fi does not have an IP address and cannot connect to the Internet.  I can access the internet by ethernet through the same router.

iMac, OS X Mountain Lion (10.8.4)

Posted on Jul 29, 2013 11:21 AM

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Briansaund

Q: My iMac wifi does not work.  Diagnostics say that my router cannot access the internet but by Macbook Air works fine through ... more

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  • by rkaufmann87,

    rkaufmann87 rkaufmann87 Jul 29, 2013 11:27 AM in response to Briansaund
    Level 9 (58,184 points)
    Photos for Mac
    Jul 29, 2013 11:27 AM in response to Briansaund

    Check to see if the router has up-to-date firmware, you will need the routers instructions for that. Also, how far is the iMac from the router?

  • by Briansaund,

    Briansaund Briansaund Jul 29, 2013 11:59 AM in response to rkaufmann87
    Level 1 (0 points)
    Jul 29, 2013 11:59 AM in response to rkaufmann87

    I doubt that the firmware is the issue.   All was working perfectly earler today.  My MacBook Air works through the same router perfectly and is sitting right next to the iMac.  My wife's IPad also works wirelessly ok.

  • by Linc Davis,

    Linc Davis Linc Davis Jul 29, 2013 6:11 PM in response to Briansaund
    Level 10 (207,926 points)
    Applications
    Jul 29, 2013 6:11 PM in response to Briansaund

    Back up all data before making any changes.
         
    Step 1
      
    Take all the applicable steps in this support article.
      
    Step 2
       
    If you're running OS X 10.8.4 or later, run Wireless Diagnostics and take the remedial steps suggested in the summary that appears, if any. The program also generates a large file of information about your system, which would be used by Apple Engineering in case of a support incident. Don't post the contents here.

    Step 3

    If you're not using a wireless keyboard or trackpad, disable Bluetooth by selecting Turn Bluetooth Off from the menu with the Bluetooth icon. If you don't have that menu, open the Bluetooth preference pane in System Preferences and check the box marked Show Bluetooth in menu bar. Test. Continue if you find that Wi-Fi is faster with Bluetooth disabled.

    From that same menu, select Open Bluetooth Preferences. If the box labeled Discoverable is checked, uncheck it. Click the Advanced button, and in the sheet that opens, uncheck the top three boxes, if any are checked. Click OK. Enable Bluetooth and test again.

    If the application called "Bluetooth Setup Assistant" is running, quit it.

      
    Step 4

    This step will erase all your settings in the Network preference pane. Make a note of them before you begin, and recreate them afterwards. It may be helpful to take screenshots of the preference pane.

    Triple-click the line below on this page to select it:

    /Library/Preferences/SystemConfiguration

    Right-click or control-click the highlighted line and select

    Services ▹ Reveal

    from the contextual menu.* A folder should open with an item named "SystemConfiguration" selected. Move the selected item to the Trash. You may be prompted for your administrator password.

    *If you don't see the contextual menu item, copy the selected text to the Clipboard (command-C). In the Finder, select

    Go ▹ Go to Folder...

    from the menu bar, paste into the box that opens (command-V). You won't see what you pasted because a line break is included. Press return.

    Reset the System Management Controller.

    Step 5

    [See related.]