A Mac without Wi-Fi is a crippled Mac. With everything you do on your Mac having a good chance of being connected to something online, you probably want to fix your Sierra Wi-Fi problems pronto. Let’s get going with exactly just that.
Slow or dropped Wi-Fi connections with Mac OS Sierra?
If your Mac fails to reconnect to your Wi-Fi network after you wake it up or when you shuttle between two Wi-Fi networks that you commonly use, the fix is probably an easy one. The following fixes might also fix your Sierra slow problems as well, especially if your Mac is slowing down only when you need to do something online.
Before we get started, I always recommend that you use Time Machine to backup your Mac. Yes, it is not a fun process and is a bit cumbersome. But then, nobody wants a Mac that stares back at them blankly, like it hasn’t known you at all, even though you have shared so many of your memories and work with it.
So first, back up your Mac before you run the following fixes!
Fix 1 – Resetting your Wi-Fi connectivity preferences in Mac OS Sierra
- Quit all applications or programs that are actively using the internet (browser, iTunes etc)
- Turn off your Wi-Fi connection on your Mac
- Enter /Library/Preferences/SystemConfiguration/ in the Finder window
- Find the following four files
- Copy these files onto a thumb drive or another folder on your Mac, just in case (Optional step but recommended, in case something goes wrong, you can paste them back)
- After backing up the above files, delete these files in the location mentioned above
- Restart your Mac
- Restart your Wi-Fi router also for good measure, before your Mac restarts
- Restarting your Mac will cause your Mac to rewrite these files, hopefully with corrections that will fix your Wi-Fi problems
Fix 2 – Creating a network connection with Custom DNS (Slightly Technical)
You might not understand all the jargon mentioned in this particular fix. But, it can help fix your Sierra Wi-Fi problems for good. Might be well worth a try if our first fix didn’t do it for you.
- Quit all your internet using applications
- Go to Apple Menu – System Preferences -> Wi-Fi -> Select your Wi-Fi connection -> Location -> Edit Locations -> + (Click on + to create new location)
- Name your new Wi-Fi connection to any name that you want
- Join the new Wi-Fi connection
- Enter your Wi-Fi connection password when prompted
- Once connected to your new connection, go to the advanced tab (bottom right)
- Click on TCP/IP – > Renew DHCP Lease -> Apply -> DNS -> + (Lower left corner)
- Enter the following DNS Server addresses in the white space that is given for DNS servers: (The following DNS addresses are Google’s DNS addresses. It is very safe to use)
- Click OK. Then, click on the Hardware tab
- Click Configure -> Manually -> Custom
- Type in 1453 as MTU number
- Click Ok
- Click Apply to save and apply all your changes
If Fix 1 didn’t work, this Fix 2 should definitely fix your Sierra Wi-Fi problems. If this fix also doesn’t work, you can just go ahead and delete this new network connection that you created, if you fear that it might harm your Mac in any way. Not that it does any harm but it is pointless to have a network connection present when it just doesn’t work.
Other fixes you can carry out to fix your Mac OS Sierra problems
If you are the type that hasn’t restarted your Mac in a long, long time, instead only using sleep, a simple restart might fix your Wi-Fi problems. Besides trying to fix your Wi-Fi with this simple fix, it is also recommended that you restart your Mac from time to time, so updates and system resets apply, to help your Mac stay up to date in terms of performance.
You must also investigate if your modem or router is working properly. Bring a friend’s laptop and see if it connects to your Wi-Fi connection. Or, you can use your phone and tablet to connect to your Wi-Fi router. If no devices can connect to your Wi-Fi router, it is obviously a problem with your router and not your Mac’s Wi-Fi receiver.
In some cases, your Wi-Fi router might have two frequencies. There have been many occasions when only one band works (2.4 GHz or 5 GHz). If that is the case, use the frequency that works.
Other fixes that you can try are to run a PRAM and SMC reset, both Mac hardware resets that will not destroy any of your user data. They are soft resets that will rewrite some configuration files that might fix your Mac’s Wi-Fi problems and even help it speed up a little. In some cases, a PRAM reset or SMC reset might cause you to re-enter your date and time information but that’s about the only thing it will require you to do on your Mac.