Apple updated OS X 10.10.1 with an eye to resolving a good many discomfiting bugs faced by Mac users. While it did succeed in getting rid of most issues, the rather poor performance of Wi-Fi has continued to be a cause of concern. Though quite a lot of tricks and suggestions have come out in order to fix it, they can't guarantee a perfect solution.
OS X 10.10.2 is still in beta version and may take some time before it could come with an answer to the sluggishness of WiFi. Hence, you have no other alternative but to find some ways that can help bring the desired result. Here are some possible tricks that may just provide you the perfect way out if Wi-Fi Isn't Working Properly In OS X Yosemite. Take a look!
If you find difficulty in connecting to internet, there may be problems with your cables, devices, network settings or ISP. So make sure, all these things are right without any flaw.
You must ensure that the network diagnostics have been taken care of. Unless they have been sorted out, you will continue to face the WiFi bug.
Always make sure you have a perfect Wi-Fi connection in order to have a consistent web browsing.
For any help with regard to WiFi, open AirPort Utility → Help → AirPort Utility Help.
Make Sure Cables Are Properly Connected
If cables are not connected properly, they can create issue. If you use an external modem, you must make sure one cable connects the modem of your computer and the other connects the modem to a working wall jack.
External devices such as modems, hubs and routers must have to be properly plugged in and turned on. Try to reset them a few times by plugging in and out.
The indicator lights on the device shows the network as well as computer connection. Hence, check it out.
Network Service and Settings
In order to get rid of the Wi-Fi issue, it is always recommended to check the settings and network service. Such as, WiFi, Bluetooth in Network Preferences.
Step #1. Choose Apple Menu.
Step #2. Click on System Preferences.
Step #3. Click on Network.
Step #4. Click on Advanced.
Step #5. Enable Change Networks.
Step #6. Click on OK and then Select Apply.
(Make sure the network service has a green indicator and the word “Connected”. For any other additional help, click on “Assist Me” button.)
If the above mentioned tricks don't seem to bring the desired solution, follow these steps –
Step #1. Click on System Preferences from Menu.
Step #2. Click on Network.
Step #3. Click on Advanced → TCP/IP.
Step #4. Enable Renew DHCP Lease.
Step #5. Once it is done, click on OK.
That's it! Hopefully, it is fixed now.
Alternately, if you still haven't got much success,
Step #1. Reinstall OS X Yosemite.
Step #2. Run the routers in “Access Point” mode.
Step #3. Switch connection to a 2.4 GHz band.
Some users have reported that after reinstalling the Mac's latest operating system, the Wi-Fi issue has been sorted out. Hence, you can try it out just in case it mightn't have been installed properly.