Yosemite (OS X 10.10) killed my WiFi :(

Reinstall Yosemite. Enter into recovery mode and just select the option Reinstall System. I had the same wifi problem and i just reinstalled Yosemite and my WiFi functions now.

Reset SMC worked for me. http://macdailynews.com/2014/10/22/fixing-os-x-yosemite-wi-fi-issues/

I posted this in another string, FWIW:

I have a MacBook Air, mid-2012, and had a variation of this problem: I could get non-SSL websites to load but not SSL sites (those with https:// at the beginning of the address).

Three techs at the Genius Bar worked on the issue for nearly an hour, trying a variety of fixes, including cache clears and removing most third-party software. I'd already verified and repaired disk permissions on the hard drive.

This is what appeared to be the problem -- an error in my Keychain configuration. We went to Finder/Applications/Utilities/Keychain Access/Keychain First Aid (who knew!). I entered my password, verified and then repaired. I had no idea Keychain had its own First Aid.

Others might try it -- wouldn't hurt....

Your right, it's all in the Home Preference folder. Toss the plists, reboot, redo prefs in app, alls good!! did this 3 days ago, everything works perfectly.

I had quite some problems when i updated to mavericks, my 5 GHz WLAN would work for short time, then disconnect, try to connect again, and so on. I solved by doing a clean installation (deleted hard drive, and did fresh install from internet) of my MBP MD101, with mavericks again. Now I've updated from mavericks to Yosemite, no problems there on either 2.4 GHz og 5.0 GHz.

Using Ubiquiti LR AP for 2.4 GHz and Netgear WNHDE111 for 5.0 GHz. The only thing is that the range of 5.0 GHz can't keep up with my 2.4 GHz (well its also a Long Range model 🙂 ) - But the Netgear 5.0 GHz AP is quite old, maybe thats the reason.

Hope this can help some of You with the frustrating Wi-Fi problems 🙂

Kind Regards

Kim

I tried nearly all the suggested remedies for fixing my wi-fi connection, which oddly enough only stopped working at home; At school and at my job it worked fine. Anyway, I finally got whatever was wrong fixed by re-installing Yosemite. I tried doing it Restart > CMD+R, but it took a long time so I connected to the wireless at school and just left my laptop downloading it and then re-installed it as though I were, re-upgrading it from Mavericks. I hope this is finally fixed for good.

Did this Keychain repair sill no joy

there is some stuff on Daily news about this.. this is a pate from there...(http://macdailynews.com/2014/10/22/fixing-os-x-yosemite-wi-fi-issues/)

MacDailyNews Take: This is not a new issue. It also happened with OS X Mavericks. We had this problem on one of our Macs running OS X Yosemite and fixed it the way we always have, by resetting the SMC (System Management Controller).

We don’t know precisely why this works, only that it has worked for us in multiple cases of wonky Wi-Fi with iMacs and MacBook Airs running OS X Mavericks and OS X Yosemite.

Resetting the System Management Controller (SMC)

Resetting the SMC on portables with built-in batteries:
1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.

Resetting the SMC on Mac portables with a battery you can remove:
1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it’s connected.
3. Remove the battery.
4. Press and hold the power button for 5 seconds.
5. Release the power button.
6. Reconnect the battery and MagSafe power adapter.
7. Press the power button to turn on the computer.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve:
1. Shut down the computer.
2. Unplug the computer’s power cord.
3. Wait fifteen seconds.
4. Attach the computer’s power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Note: Resetting the SMC does not reset, or otherwise change, the contents of PRAM, which is also known as NVRAM on Intel-based Macs.

I did all of the recommendation individually, but no success.

The following solution enable me to have internet for a good 3 hours (Enough to download Mavericks).

1.

Turn off your wifi, go to finder and press COMMAND - SHIFT - G, and then type /Library/Preferences/SystemConfiguration (Caps are important according to the advisor) and then press enter.

Inside the window, look for NetworkInterfaces.plist. (Delete), and then Preferences.plist. (also delete).

Go to the apple icon on the bar and reset your mac.

2. Finder/Applications/Utilities/Keychain Access/Keychain First Aid > Verify then repair

3. Resetting the System Management Controller (SMC)

4. Do not connect any bluetooth (Whenever I connect, I lose connection quickly)

5. Search in Google how to create a bootable Maverick usb (You will need 8GB + Maverick.app + LionMaker app which is free).

6. Follow the website that explain the instruction and then you are done with the Maverick installation.

Before going to sleep, I left a 10 hours Youtube video stream and when I woke up, the video was still playing.

So Maverick +1. Yosemite 0.

I personally suggest that you revert to Maverick until Apple developer team can fix this issue in a permanent way instead of doing fixes yourself, putting too much hope and then lose connection again.

Cheers,

Chungy

What type of Wi-Fi are you using? Is it home one (WPA2-Personal)?

I have no any problems with my home Wi-Fi WPA2 (using UniFi Access Point), while having real issues with WPA2-Enterprise.

Pity, but even after Apple release of any patch/update you'll never know if it helps in your case if not having Yosemite installed.

Btw, did you try the trick with deleting Wi-Fi service and recreating it under different name?

Hi Peper,

I am using a WPA2-Personal. Haven't attempt to bring it at work to see if it work.

I did tried to trick naming Wifi1 or Wifi2. It works at top 1 hour usability.

We´re in the same boat. :/

Apple should, at least, say something official... at least ´We´re working on it...´.

So far I´m thinking about downgrade and use Maverick until Apple release a fix for this issue.

My MBP was dropping its connection every 2 minutes for days now. Tried many of the fore mentioned solutions with limited success.

I just turned off the "Handoff" feature (Settings - General) on my iPhone 5s IOS 8.1 and now my MBP connection is remaining solid.

Unbelievable and sad that this has gone on for this long.

Spent ages on this today both with my broadband provider and for the last 2 hours with Apple Support. Did all the various resetting etc of the Pram, SMC, deleted Cache etc, started in safe mode, umpteen restarts. I was getting download speeds of 0-2mb/s v 43 on my wife's mbp with Mavericks.

The final solution the Apple guy gave me to try was to create a new wifi location which we just left as untitled. Once we done this I was flying again. Worth a try for anyone still having problems.

Try installing Java 8. Download the Mac version from another device and transfer via USB drive (copy and paste) http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.h tml