How To Fix WiFi Connection Problems in Mac OS X Lion

If you’re having any WiFi connection issues (such as frequent dropouts, slow speeds or you simply can’t connect) with Mac OS X Lion, there are a few things that you can do to troubleshoot and hopefully restore connectivity to your Mac. WiFi can be the most convenient way to connect to the Internet, but it’s not occasionally without its difficulties – possibly problems with your Internet Service Provider, the local access point (i.e. your router or hub), or other technical issues (hardware or software) with the Mac.

Follow our brief guide below to troubleshoot some of the most common WiFi issues you might encounter with Lion.

Check Your Mac’s WiFi Settings

The first thing to do when you’re experiencing WiFi problems is to check and validate your network settings in System Preferences to make sure everything is setup correctly.

1. Open System Preferences and select the Network icon, which is in the Internet & Wireless section

Network Settings
Open the Network settings in System Preferences

2. Click the Advanced button at the lower right to view more details about your network connection

WiFi Advanced Settings
Click the Advanced button to open up more options

3. Under the TCP/IP tab, under most circumstances you’ll need the Configure IPv4 item set to Using DHCP. The reason is that in OS X Lion there have been some reports that manual configuration causes issues (though this may only be with early versions after the OS was first released)

Network Settings (TCP)
Set TCP/IP to DHCP

4. You should also look at the other network tabs such as Wi-Fi, and check that the network you want to join is shown in the list. Drag the networks into the desired order, for example you may as well move the network that you want to connect to right to the top of the list to make sure your Mac looks for that one first

Network Settings WiFi Tab
Rearrange the wireless networks into the desired order

It’s also definitely worth just plugging in a network cable between your router and your Mac, to check whether basic Internet connectivity is working. If you can’t even connect to the Internet with a cable, then it points to a broader problem that may not be related to WiFi.

Remove and Re-Add The WiFi Service

One thing to try when you’re experiencing wireless network problems is to delete and then re-add the WiFi service.

Follow the steps below:

1. Open Network settings under System Preferences

2. In the left-hand side panel, select the Wi-Fi icon and then hit the Delete button (the small “-” icon) and confirm when prompted

Delete WiFi Service
Use the "-" button to remove the WiFi service

3. Once the WiFi service has been deleted, add a new one with the Add (“+“) button, and then enter the name of the new connection followed by Create. This establishes a new WiFi connection with the default settings. Just go through the various tabs to make sure WiFi is configured correctly (items such as the password) and try connecting to your wireless hotspot again. If prompted, re-enter any details that may have been lost when deleting the service

Add New WiFi Service
Add a new WiFi service

Check Your Wireless Router Settings

Your wireless router is normally provided by your Internet Service Provider (ISP) when you sign up to an Internet, phone or TV package. Sometimes however it’s necessary to reset the router (there should be a small reset button on the back), or even login to it and play around with the settings to use the optimal configuration. Unfortunately, quite often the administrator password isn’t provided to customers to stop them changing the default settings accidentally. If you know the password, it’s definitely worth logging in to the router to inspect the configuration.

To get to your router, open a new tab in Safari and enter the following address in the address bar:

http://192.168.0.1

This should take you to the router’s login / administration page where you need to enter its admin user name and login password. If this address doesn’t work, you can try one of the other default addresses commonly used by routers, such as 192.168.2.1 and 192.168.1.1

Make sure that you take a look at the security settings (such as the wireless key) and inspect the logs to see if there are any clues about potential issues. Every router is different, so there’s not one set of specific instructions that works across all models, but in general a few tweaks can usually help resolve your WiFi connection issues. For example, if there are dozens of WiFi hotspots in the area where you live, you might be subject to wireless interference issues if someone else has configured their router to use the same wireless channel – try changing it from the default channel to something different. You can also change the security settings (for example to use WPA or WPA2) or remove them completely, to see if that makes a difference.

Try Connecting Other Devices

It might seem pretty obvious, but you should always try connecting another device over WiFi to see if it’s actually your Mac or the wireless network itself which is experiencing technical issues. If you can successfully connect another computer, iPhone or tablet for example, then it points to an issue with your Mac rather than the network kit or Internet connection.

Also, you should of course try connecting your Mac to another wireless network to see whether the problem persists. If you can connect to another WiFi setup, then consider noting down the router’s configuration and setup details and comparing that to your own.

Reset PRAM and SMC

Your Mac’s Parameter RAM (PRAM) memory can occasionally be the cause of various technical issues, so if you have WiFi woes and nothing seems to work you could try to reset it. Follow the procedure below:

1. Shut down your computer

2. Locate the Command, Option, P and R keys. You’ll need to use these in a moment in step 4

3. Turn on the computer

4. Press and hold down the Command, Option, P and R keys before the grey screen appears

5. Hold down the keys until the computer restarts and you hear the startup sound for the second time

6. Release the keys

The PRAM should now be reset to the default values. Try connecting to the Internet by WiFi again when your computer has fully rebooted.

Another approach is to reset the main SMC chip (System Management Controller), which may resolve issues related to fans, lights, video and power. If you’ve tried everything else and you still can’t get your WiFi to work, you may as well reset the SMC, as there aren’t any negative consequences of doing so.

Here’s how:

1. Shut down the computer

2. Plug in the power adaptor

3. Press the Shift + Control + Option keys and the power button at the same time

4. Release all the keys and the power button simultaneously

5. Press the power button to turn on your Mac

Delete The Internet Preference Files

You can try deleting some of the Internet preference (.plist) files from your system Library folder. Sometimes, corrupted preference files can be responsible for things not working correctly. Follow these steps:

1. In Finder, press Command + Shift + G and in the drop-down dialogue box, enter ~/Library as shown below:

System Library Folder
Open the system library folder

2. Locate the following preference files

  • com.apple.internetconfig.plist
  • com.apple.internetconfigpriv.plist

3. Copy the files somewhere (e.g. to your desktop) as a precaution and then delete them from the Library folder. Any similar files named com.apple.internetconfig[...] can also be safely deleted

4. Turn your Mac’s airport off and back on (just click the airport symbol in the menu bar and choose Turn Wi-fi Off)

Call a Professional!

Finally, if you’ve exhausted every possible avenue and still can’t resolve your WiFi connection issues, it might be time to concede defeat and take your Mac to the Apple Store to see if they can resolve the issue. Most problems with your Mac should be fixable by the technicians there, but there are of course lots of resources on the Internet that you can also use.


Speed Up Mac Apps Reviewed - 2014

meOver 15 years working on Macs has taught me that the most common problem Mac users faces at some point is computer slowdown. I have tested the best Mac Cleaning and Speedup Apps so you can make an informed choice - Check it out here. Christopher Lee, founder chriswrites.com

Comments

  1. Jose says

    Try setting MTU to 1300 in Network.

    Network -> Advanced -> Hardware -> Congifure: Manually, MTU Custom, 1300

    That solved my WiFi problems

  2. cml says

    Dude,you saved my life tonight.. I’m a developer and I have a lot of work to do for tomorrow and this fuckin wifi wasnt working…. thank you so much.. I want you to know that there is a man you saved his life anywhere in the world :)

  3. cml says

    Dude,you saved my life tonight.. I’m a developer and I have a lot of work to do for tomorrow and this fuckin wifi wasnt working…. thank you so much.. I want you to know that there is a man you saved his life anywhere in the world :)

  4. Peter Damby says

    Thanks, it seems that you have a very large knowledge on this subject. At my workplace everybody with pc can get on net, but we are 3 persons with mac who can’t. We can see the router on airport, but it seem that it would not aloud us to get to server. Any ideas?

  5. Peter Damby says

    Thanks, it seems that you have a very large knowledge on this subject. At my workplace everybody with pc can get on net, but we are 3 persons with mac who can’t. We can see the router on airport, but it seem that it would not aloud us to get to server. Any ideas?

  6. Nathan Todd says

    Handy thanks! I’ve discovered (I hope) that the problem with my wifi especially on mac devices showing an exclamation ! mark and taking ages to connect (or sometime connecting then disconnecting after waking from sleep) was due to Connect mode select: Always-on Connect-on demand being set to Connect on demand instead of always on

  7. gregg says

    Thank you! I spent about 4 hours reading about “possible” solutions but yours did the trick!

  8. gregg says

    Thank you! I spent about 4 hours reading about “possible” solutions but yours did the trick!

  9. pm says

    Thanks for nothing Chriswrites. Very ambiugous instrucitons.
    I rarely comment on articles, but I will here to warn you of a problem with your instructins.
    Got to step 2 on the remove and re-add wifi. Removed wifi service, went to re-add, but your instructions are unclear, guessed that I was to add the name of my wifi service and now I have a status message that says my wifi service does not have an ip address and cannot connect to the internet. Nor can my mac find the network. Can’t get any further than this and as for “just go through the various tab settings to make sure wifi is configured correctly” just too too vague. Luckily i have clicked the revert button and undone these poor instructions. Please review these instructions for users of os Lion for mbp version 10.7.5. They are NOT helpful.

  10. Mimi says

    I have the same problem
    When deleted the wifi could not connect it again saying no IP address for the wifi?

Leave a Reply