One of the benefits of Apple products is that the company has gone to great lengths to make the underlying technology invisible, to the extent possible. Think about Internet connectivity. Remember the lengthy screech and squeal of a modem handshaking with your ISP? Today, thanks to wireless networking (and broadband Internet connections), you can open your MacBook Air and be browsing the Web within moments.
At least, you can when Wi-Fi is working properly. As a consultant, I occasionally come across a Mac that insists that you choose the Wi-Fi network from the menu bar icon every time. Or perhaps the Mac drops the Wi-Fi connection, or won’t connect at all. Here are a few troubleshooting steps that should fix it. (Note that I’m talking just about the wireless network connection here, not Internet connectivity, since that’s another whole ball of wax.)
Restart the Mac -- Just do it, and if you’re helping someone else, make sure he or she does it. You may think that restarting is obvious, but several times my clients have told me they restarted, and, after two hours of troubleshooting, admitted they hadn’t actually done so, because they thought it would take too long. A restart fixes many ills, including recalcitrant Wi-Fi, so it’s always worth a try. If that doesn’t work…
Restart the Wireless Router -- The next step is to reboot the wireless router, often an AirPort base station. Just as many issues are solved by restarting the Mac, the same goes for Wi-Fi hardware. That hardware may come in the form of a single device from the Internet service provider, a cable/DSL modem with Wi-Fi built in. Or, you may have a standalone cable/DSL modem connected to an AirPort base station, Time Capsule, or third-party wireless router.
These devices often lack reset or power switches, so the easiest way to restart them is to pull the power. (You can also restart an AirPort base station using AirPort Utility in either Mac OS X or iOS, assuming, of course, that you can connect to it at all.) Unplug the device (either end; it’s generally safest to unplug the cable that goes into the device rather than risk pulling the wrong cord from the wall) and wait a few seconds to be certain any internal capacitors have discharged.
If you’re dealing with a separate cable/DSL modem and wireless router, restarting the modem won’t generally affect Wi-Fi. But if you do unplug the modem as well, make sure to plug it in first, wait a minute or so for its lights to indicate that it’s back online, and then plug the wireless router back in.
Once the wireless router is back up (this can take another minute or two), see if the Mac can connect to the Wi-Fi network. If not, restart the Mac to encourage it to reconnect, and if even that doesn’t work, read on.
Recreate Your Preferred Network -- It’s possible that the Mac’s wireless connection settings have become corrupted. To fix this, delete the connection and recreate it. Follow these steps:
Open the Network pane of System Preferences.
Select the Wi-Fi connection in the list of network services on the left.
Click the Advanced button at the bottom right of the window. In the Wi-Fi view’s Preferred Networks list, you’ll see every wireless network you’ve ever used. This is where your Mac remembers Wi-Fi details that enable it to connect automatically the next time that network is available.
Find the desired wireless network name in the list and select it.
Click the – button below the list to delete that network.
Click the + button, and in the dialog that appears, click the Choose a Network button.
Wait for the right wireless network to appear. Select it and click the OK button, entering the network password if prompted.
Because it’s your most frequently used network, your home or office wireless network should appear at the top of the Preferred Networks list. If it’s farther down, drag it to the top to make sure it’s used preferentially.
While you’re there, take a moment to peruse the list. Every wireless network you’ve ever joined is listed. A few may be from places you’ll never visit again. There’s no harm in having a long list, but if you took a trip to Hawaii, you probably won’t need your hotel’s wireless network again, so you can remove it.
Restart your Mac to see if your it joins the network automatically. Are you on, and does it stay on? If yes, congratulations! If not… onward and upward.
Create a New Location -- A little-known feature of the Network preference pane is the capability to create multiple “locations.” This feature enables you to maintain separate sets of networking preferences for different places. For example, you could create a “Mobile” location that removes all network services except Wi-Fi and Bluetooth, or a “Work” location that includes only Ethernet.
Creating a new location gives you a clean slate of wireless network settings and may clear up any remaining glitches. Follow these steps:
In the Network pane of System Preferences, choose Edit Locations from the Locations pop-up menu at the top.
Click the + at the bottom and type a new Location name, like Home or Work. Click Done.
You’ll notice that your list of network services will clean itself up.
Using the buttons at the bottom, you can add or remove any network services that you never use, and set the order by choosing Set Service Order from the pop-up gear menu. Once everything is adjusted (probably with Wi-Fi at the top), click the Apply button.
It’s a good idea to restart your Mac to make sure everything is refreshed; you may be asked for your Wi-Fi password again. Does your Wi-Fi stay connected? It should! This solution hasn’t failed me yet.
Last Ditch Efforts -- Of course, there are a number of other reasons why Wi-Fi connections can be problematic, and some of them can be difficult to fix. For instance:
It’s conceivable that your wireless router’s settings have become scrambled to the point where restarting it isn’t sufficient. To resolve this, reset it to factory defaults (consult the manual) and reconfigure it from scratch. It’s best to write down all the settings before you nuke its little brain.
Worse yet, wireless routers do die, despite their lack of moving parts. If no computer can pick up the wireless network, and a factory reset doesn’t help, it’s possible that a new AirPort base station is in your future. Luckily, you usually get new Wi-Fi flavors when you upgrade. If you have a combined modem/wireless router, you may have to call your ISP for a replacement.
If your Mac can’t see any other wireless network at all, it’s possible that its AirPort card has failed. That might be reason to visit the Apple Store, but if you’re feeling ambitious, has free repair guides for nearly everything you might want to replace, along with tools and replacement parts for sale.
Finally, and most frustratingly, Mac OS X upgrades are often accompanied by numerous complaints on the Apple Support Communities forums about Wi-Fi dropouts. The suggestions above will often resolve these problems, but sometimes the solutions are specific to Wi-Fi settings (like switching to a particular channel instead of letting it be chosen automatically) or to corruption in areas outside of what would you’d normally think. If all else fails, calling Apple is your best bet.
Conclusion -- There’s little more frustrating than being forced to connect manually to your favorite wireless network repeatedly, or not being able to connect at all, so I hope this advice will help you avoid that inconvenience. If you’ve run across other useful solutions for solidifying unreliable Wi-Fi connections, let us know in the comments!