WiFi unable to turn on [duplicate]

I have a MacBook Pro 2009 running MacOS El Capitan. Recently the Wi-Fi has stopped working.

When I click on the Wi-Fi icon it displays the message "No hardware installed", but Ethernet still works.

Is there any way of fixing this by using a Wi-Fi dongle or something of the sort, if so do I need a specific dongle and how do I install it?


Solution 1:

If you are getting the message "No hardware Installed" it means that macOS is not detecting your WiFi adapter for one of two reasons:

  • It's not installed (it physically doesn't exist)
  • It has failed

Chances are it's the second option.

You can confirm this by running Apple Hardware Test (AHT). Hold the D key while booting from a powered off state with the AC adapter connected.

Regardless if the first or the second, you will probably have to replace it with another Airport card

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ifixit.com has an excellent tutorial and step-by-step guide on how to replace the board. It's a time consuming repair - I wouldn't say difficult, but more detail oriented. If this is not your cup of tea, I recommend taking it in for service.

Solution 2:

I had this same problem. I reset NVRAM and SMC to no effect. I also ran the Apple Hardware Test and it came back as a hardware problem. But...

But then I did this, and my wifi was back, working just like new.

  1. Switch to Finder

  2. Click on 'Go' (top menu) -> 'Go to Folder...'

  3. Copy and paste this into the field: /Library/Preferences/SystemConfiguration

  4. Find and trash NetworkInterfaces.plist, com.apple.airport.preferences.plist, com.apple.wifi.message-tracer.plist

  5. Reboot

I would suggest making a copy of this file, naming it something different and storing it on your desktop before deleting the file - just in case. But this worked for me. Hope it works for you.

Solution 3:

Try resetting the NVRAM and SMC first before going out and spending money on a new WiFi adapter. You can do this by:

NVRAM

  1. Reboot the Mac and immediately hold down Command + Option + P + R keys together
  2. Continue holding all Command+Option+P+R keys until you hear the Mac reboot sound again, then release all keys concurrently

SMC

  1. Plug the laptop into a power source
  2. Press and hold all of these keys at the same time: Control + Shift + Option + Power
  3. Release the keys
  4. Press the Power button to turn it back on

If that doesn't fix it, then you might need to buy an adapter. There are a lot of good ones out there that work with Macs. I would just go to your favorite online retailer and search WiFi adapters for Mac. That should bring you plenty of options.

Solution 4:

It could be the ribbon cable connecting the airport board to the logic board, allegedly they wear out.

There is a good explanation here: http://warrantyvoidifremoved.blogspot.com.au/2014/01/repairing-intermittent-wifiwireless-on.html?m=1