Q: iMAC 21" WIFI failing after 10.7.4 update

I've tried WPA and WPA2 (which I'm still on). The problem still occurs. So sadly I think like a few people your problem will eventually come back.

The Apple engineer contacted me too. I'm man enough to admit I was wrong about them looking at the issue. I'll send them the debug info tomorrow.

So far the change to WPA2 has worked for me.  For several hours I've had no drops. 

But since the May 12 install of 10.7.4 I've had intermittent drops.  The occurrence and duration of disconnects seems random.  So I'm not convinced the connection problem has been resolved by changing to WPA2 although I've got my fingers crossed that it has.

Let's see the level of commitment they can sustain in finding a solution.

Glad I found this thread; I just got a brand new 27" iMac, having this same issue. In addition, the screen flickers, the performance with Lion has been terrible, the wireless keyboard keys get 'stuck' and repeat endlessly even though I'm not holding them down. Even TextEdit crashes. And now tonight I experienced this same issue with 10.7.4 - my internet sharing is failing. I'm actually a professional iOS developer and I've used nothing but Macs for the past 19 years. But this latest iMac, mixed with Apple's frightening new political agendas with their locked down systems, Gatekeeper, etc... I guess this is the straw on the camel's back for me. I'm calling the Apple Store and asking to get my money back. Not sure if they'll do it but I'm hoping I can get a refund. I'll still have to use my work MBP for Xcode at my job but I'm going to finally make the switch to Linux or Windows after a lifetime of Mac dev. Those systems have problems of their own, but at least I have more flexibility with the hardware, a larger user base to help me troubleshoot issues, and I can participate in a software dev community that can distribute apps that don't have to be codesigned.

Sorry, this post went off on a bit of a tangent. Guess I'm venting.

But anyways, just wanted to chime in that I'm also affected by this bug. Unlike you guys though I no longer have the time or energy to keep finding work-arounds for broken products. $1.7k brand new computer, there's no excuse for it to be malfunctioning so severely on so many levels.

Apple has definitely gone astray in the past few years. It makes me sad. Don't want to switch to horrendous-looking Windows but I need to find a computer I can actually use.

i've opened a bug report at bugreport.apple.com and got a message that it's duplicating other open bug report,so apple knows about the issue...if we want it to be solved ASAP we need to find the reason of the problem or type of macs that do have the issue and those that doesn't.

LET'S DO LIKE THAT:PROVIDE YOU OS X BUILD,MAC CONFIGURATION,WHICH ROUTER DO YOU USE(MODEL AND SPEED),ENCRYPTION TYPE,YOUR MAC OS X LANGUAGE AND YOUR COUNTRY.

I've posted in another thread:

https://discussions.apple.com/thread/3947671?start=15&tstart=0

Maybe this works…

Somebody tried to make a NVRAM/PRAM reset??

http://support.apple.com/kb/HT1379

Bit distressed to read your post.  I moved to Mac 4 years ago and was pleased to leave Windows behind.  The 10.7.4 wifi drop issue is a wake up call.  But the OS changes in Lion may be just as bad in the sense they've taken a highly functional OS and pretty much trashed it.  Not sure what my options are at this point but Windows is getting moved back on the list of alternatives. 

JohSm wrote:

 

Any one else with problems having VMWare Fusion 4 installed prior the 10.7.4 OSX update?

Nope, never installed any VMWare software, still suffering from the exact same problem you described in your original post. I don't think that's the cause of all this.

since starting to view this thread about 13 days ago, my random wi-fi dropouts seem to have stopped......could it be that Apple are able to update the OS in stealth mode, for instance whenever anyone checks on updates? either that or my i7 iMac 2011 is actually able to evolve.......a miracle indeed!!

Not to rain on your parade, but in my case the drops have been random --  no discernable pattern, no rhyme or reason, not always a ready explanation for a change in pattern.  

Sharing from my iMac to my iPad and MacBook Pro has been okay for 24 hours now. Here's the configuration, based on instructions from Apple Care Senior Advisor:

Firewall is OFF

Preferences --> Sharing:

     Screen sharing, Scanner Sharing, Web Sharing and Internet Sharing are checked.

     WiFi Options: Security is set to NONE. (to do this: uncheck Internet Sharing, you should have "Share your connection from:" then select how you connect (I connect with ethernet to a cable modem) "To computers using:" check WiFi. Then click on WiFi Options, and for security select None. (I think it's None - frankly I'm afraid to touch anything) - anyway, just make sure there is no security on your sharing.

     Network preferences still shows self-assigned ip for the WiFi, but now I understand that the WiFi is a separate function from Sharing.

At one point last night, I did have to restart my iPad to make it connect. I was getting a weird chain link icon in the upper left of the screen (where the wifi connection should be)

The sense I got from the Senior Advisor is that they know there is a problem and they are addressing it. How long it will take is another story. He also said that they are not going to leave us with our Internet Sharing unsecure, so they are working on this.

Tried the PRAM reset today and it did not solve my problem. Only cure I have got is that after iMac wakes from sleep & no wireless is to restart the machine.

It is ridiculous that so many people are reporting this issue for weeks and a fix has not yet been released.

Anyone know if is possible to remove 10.7.4 update ?

Apple has already contacted some users from this thread to try to reproduce the problem and send them the logs. So they are already investigating, but even if they find and fix the bug I imagine that it's going to take some time until they release the update (they have to test, etc.)

In the meantime, what worked for me was to downgrade the WiFi driver to the previous version. Search this thread, there are at least two posts that explain how to do that!