Wifi won't turn on since upgrade to Lion

I have tried this on both iMacs in my stable. It seems to be working with one or two Sleepa and Wakes. Time will tell. I hope it will be the solution. It makes sense.

I also went to the Advanced page of System Preferences => Network => Wi-Fi and deleted the Preferred Network that was there.

I then Shutdown the computer and re-started it.

I went back to System Preferences=> Network and Wi-Fi clicking on the Plus + at the bottom of teh left-hand panel.

I then clicked on Advanced and added the Preferred Network name (My router), selected the Security from Menu choices and added Password for this network

This all seems to have done teh trick. As I say, time will tell.

I have a time capsule and this worked...

I tried everything under the sun and nothing worked. I talked to three Apple techs and nothing worked. The forth one seems to have given me a fix.

1) Go Apple symbol (top left) and select "About this Mac".

2) Then "System Report".

3) Then go down to "Wifi" ... see what channel your wifi network is and see what other networks are showing as their channels. Mine was channel "11" but so was five other networks. They must have been interfering with each other.

4) Take note of what network channels are not in use...1-11.

5) Go to "Spotlight" (the search symbol in the top right) and type "Airport Utility". Go to it.

6) Click "Manual Setup".

7) Click "Wireless".

8) Change your channel...I changed mine to 9. Then update and close out. It should reset your time capsule and should work.

I didn't work for me.

There seem to be a lot of people having this problem.

Does anybody know of an official reaction from Apple?

This seems to be an issue that affect many users, and it happens to make the computer not very useful...

I tried all of the fixes mentioned and they didn't work. The only thing that resolved the issue for me was to do a clean install of Lion with the wifi card removed. I then updated to 10.7.2 and re-inserted the wifi card. After this is was detected correctly and has worked fine since.

It seems to me that the problem is with the Snow Leopard to Lion Upgrade process.

I've had this problem with my early-2008 17-inch MacBook Pro since one of the later Snow Leopard releases. It was not an issue under Leopard or the early Snow Leopard releases. I've tried everything that's been listed in this forum, and may other things to boot.

Card type: AirPort Extreme (0x14E4, 0x8C)

Firmware Version: Broadcom BCM43xx 1.0 (5.10.131.36.11)

What's more, I've taken my computer to the local Apple Stores and had the logic board and the AirPort card replaced under AppleCare. When the problem again occurred a few months later, I had the screen itself (housing the antenna) completely replaced.

In effect, Apple replaced the entire computer. This fixed the problem, again, for awhile. Perhaps another few months. Then it returned. Now the computer it out of AppleCare warranty.

I didn't experience the problem with 10.7 or 10.7.1, but it returned again directly after the 10.7.2 update.

The only real solution I've found is using a Linksys ExpressPort card for wireless. I have zero wireless problems when using the ExpressPort card. Since this laptop is just used inside my house and not for travel, this is a borderline acceptable solution for me. It sure is ugly though.

I'm extremely disappointed that Apple hasn't addressed or acknowledged this problem, which is clearly not isolated. My experience suggests, at least to me, that the problem started with a Snow Leopard update. It's been a problem ever since. My experience also suggests that hardware repairs do not address the situation in any meaningful way.

You and I seem to have the exact same problems. People have talked about this being a Lion Problem but I had the problem with Snow Leopard. I would have hoped a clean install with a brand new OS (Lion) would hav resolved the problem. Like you, no luck.

Lion (and Snow Leopard) seems to activate a security setting when another wifi device is interfeering with yours and it may shut off access. That is, in my opinion, why this may be happening. But the steps below have worked for a ton of people and me...

1) Go to Apple symbol (top left) and select "About this Mac".

2) Then "System Report".

3) Then go down to "Wifi" ... see what channel your wifi network is and see what other networks are showing as their channels. Mine was channel "11" but so was three other networks. They must have been interfering with each other.

4) Take note of what network channels are not in use...1-11.

5) Go to "Spotlight" (the search symbol in the top right) and type "Airport Utility". Go to it.

6) Click "Manual Setup".

7) Click "Wireless".

8) Change your channel...I changed mine to 9. Then update and close out. It should reset your time capsule and should work.

I have tried this. Sometimes it works and sometimes it doesn't, like every other fix I've encountered over the last 18 months. Just to reiterate, I have read everything in this thread and tried it all.

The fact is, when I use the Linksys ExpressPort card I can use the exact same wireless channels and settings as I use when the AirPort card is working. The difference is the ExpressPort card never, ever fails out on me. I have conducted these tests using both later versions of Snow Leopard and early versions of Lion in several different physical locations and with different access points.

This problem always, always returns. Sometimes it take minutes, sometimes it takes hours, sometimes it takes days and sometimes it takes months. But it always comes back.

First off, I haven't read all of the posts, so if I am reposting old info, I apologize. Last week when I was out of town, my Macbook Pro dropped the wifi connection and it appeared to be gone for good. I don't recall the exact messages I got, but bottom line was there was no way for me to turn it back on. I plugged in an ethernet cable, got back to the net and started searching. I can't recall where I found it, but here is the gist of what someone posted, and it worked.

1. Try going to System Prefrences>Network

2. Highlight Wifi and Delete (in the adapters list) by click the minus button on the bottom of the list

3. Add the Wifi adapter back in

I did this and my wifi was miraculously (in my eyes anyway) restored. I used it the rest of the time that I was out of town and it worked fine. I don't know if it's of importance or not but at my beach house I use a Linksys router and at home an airport extreme. My Macbook never drops wifi at home, but this is the second trip since Lion installation and it's done it both times on the Linksys.

The first time it happened at the beach, I searched this thread, tried all the various suggestions and nothing worked until I went home to my airport extreme. When I booted the computer at home, wifi came up...after about 20 minutes, and worked fine until I went back to the beach last week.

Don't know if this will work for you, but it has for me.

Wow, in 10.7.2 this issue became WORSE. 10.7.0 its was meh, but manageable. 10.7.1 the issue went away. 10.7.2 It's back with an uber vengence.

So for those of us with 2008 Macbook Pros that seem to continue to have this problem, what can be done? Are we supposed to just treat these very expensive laptops as semi-useful? Wifi these days is pretty vital to the use of a laptop. This problem was occuring while under warranty but was treated as a software issue. Many patches and updates later, and now an entire new OS install, and the problem persists. At what point is there some sort of recall issued by Apple to correct what clearly seems to be faulty hardware? I saw one post here say even after swapping out the wifi card the problem persists? For my first major mac purchase, I'm beyond frustrated.

Honestly, at this point I do not expect this issue to be addressed by Apple, as the affected computers are no longer under warranty and the issue was not addressed in any meaningful way when the computers were covered.

Like I said, I had my motherboard, AirPort card and screen replaced because of this issue when my computer was covered by AppleCare. This involved two different repairs jobs in 2010 (first the AirPort card and motherboard, next the screen/antenna casing). Apple replaced everything in the computer related to WiFi, and the problem still returned after a few weeks/months.

I agree with you completely that broken WiFi is a serious issue. It's so serious that after going to extremes to try to resolve the issue with Apple, which either can't or won't fix the problem, I have given up and just installed a Linksys ExpressPort WiFi card. I expect my 2008 MacBook Pro will use this card until the computer gives up the ghost for good.

I am wondering if it could posisbly be a temperature issue? I have no idea where this card is located but if it's not keeping cool, maybe that's killing it off? Seems like a lame explanation but the fact it is totally random is beyond frustrating.

For all the people in this forum that have applied the various fixes and claim it worked for them, I am curious if it is still fixed or if the problem returned and they've just given up on a solution?

there is yet no permanent fix; the problem returns 1 hour, 1 day, 1 week later. everyone has given up.

l'aéroport est plus mort que mort

So I really hate to even suggest this but I'm doing so because I believe this problem is significant. Has anyone thought about a class action suit to force Apple to correct this problem either through replacement systems or at least some sort of repair. Though it seems evident a repair isn't going to correct it. As I understand it the problem doesn't persist with newer machines, only the 2008 MB Pros?