iMac 2011 - no wifi connection after sleep under Lion

same problem, with Lion 10.7.3 ... very annoying

I am disappointed there is no solution for now

It would appear the 10.7.3 update fixed problems for some, and caused problems for others. Apple may have fixed it already, so try downloading the 10.7.3 Combo updater again if you haven't done that in the past 24 hours or so.

Here is the link: http://support.apple.com/kb/DL1484. I suggested doing that in step 4, in case nothing else works.

Here are some things to try first that may alleviate it, in order of increasing inconvenience:

1. Try creating a new, temporary user account. Log in under that account to see if its behavior is any different. If it is then it will provide a clue toward resolving the problem. Delete the temporary account when you are finished with it.

2. Go to System Preferences > Network. Click the lock to authenticate, if necessary. Then click the gear icon under the network interfaces like so:

Whatever service order you have set, drag Wi-Fi either to the top (assuming it's not already there) or away from the top if it was already there. Click OK and then Apply. Sleep the system then wake it again to observe any changes.

3. Click Wi-Fi in the above then click Advanced. Select all the networks your computer has ever joined and delete them with the "-" button. OK then Apply again. Select your network under the AirPort icon to re-join it. Sleep and wake again to see if that did anything.

4. If you have not done so already download and install the 10.7.3 Combo updater. It is a more comprehensive installer than the one available using Software Update, and may fix some problems.

The IPv6 change I suggested earlier was not a permanent fix for me.

You may have done some or all of these already but perhaps there is something you have not thought of. If nothing helps we may just have to wait a bit longer for Apple to release a fix.

Thank you very much for taking time to answer.

I'll try all,

for now point 2 and 3 haven't solved anything...

has is solved YOUR problem John ?

The 10.7.3 update solved it for me. Wireless has been very relialble since then.

My other suggestions solved similar problems in the past.

Hi, what you can do is push the power button in the back of the computer to start rather than using the keyboard or the mouse. Henceforth, you should push the power button to wake it up. I hope this helped! 🙂

So after installing the 10.7.3 update I had to manually connect everytime I turned my MacBook on or woke it from sleep. Reinstalling 10.7.3 using the combo update has fixed this. At least so far it has connected every time. What ***** is this required downloading a gig and a half file.

lucky guy, still experiencing my problem !

really disapointing from Apple... !

Or maybe it's my computer ?

Anyway can I do a rollback to 10.7.2 ??

Did you try Step 1 (create a temporary account)?

The only way to revert to 10.7.2 is to use a Time Machine backup.

I tried temporary account --> same issue

:-(

another information :

I noticed that in the network setup screen, when I want to close the little lock to restrain further modifications, it won't close. Weird !

So are you saying you downloaded the combo updated off the Apple support site and tried installing it?

when I want to close the little lock to restrain further modifications, it won't close.

That is a major clue that something is not right.

First find Keychain Access in your Utilities folder and launch it. Click the Keychain Access menu and select "Keychain First Aid" like so:

Authenticate with your password, select Repair and hit Start. If it reports anything other than "no problems found" then stop right there and see if that fixes anything.

Quit Keychain Access.

If nothing has changed and you are willing to perform a little more work, consider the following. Read the whole thing first and be prepared to reconfigure any or all of your system-specific preferences such as having to select your AirPort network and system sleep settings. In other words don't complain if this leaves your system in even worse condition. OK?

Go to the Finder and select "Go to Folder" like so:

then type the following exactly as written (better yet, copy and paste it):

/Library/Preferences/SystemConfiguration

Click Go, then find the files called

com.apple.airport.preferences.plist

com.apple.PowerManagement.plist

preferences.plist

Drag them all to the Trash.

Restart your computer.

After you log in again you will probably need to select your AirPort network and adjust your system sleep settings. Other system preferences may also have been modified by the above.

See if that changes anything.

First of all, thank you for all the time you take helping with this problem.

I tried the Keychain, and everything is all right.

I will try to delete de plist files tomorrow,

are you shure this could help ?

Right now, I have rebooted the computer and the little lock works fine.

I bought this iMac 3 months ago, it is brand new for me, and I was really enjoying the "near perfection" from Apple. This WiFi problem, I am sure, comes with the new update since I didn't change anything on my computer.

I am bothered I thought Apple would test the updates befores releasing it : but I know some of us do not have this issue... well it's weird.

I do not know if it will help but deleting the .plist files will force OS X to create brand new unadulterated copies with default settings. The idea is to eliminate any possibility that the preferences used by Network were somehow corrupted for unknown reasons.

Deleting the .plist files is fairly harmless, but I doubt it will result in anything better than reinstalling the OS as you already did. That should have worked.

This Wi-Fi "wake from sleep" problem has been a longstanding issue with Lion. I am as frustrated as anyone that it hasn't been completely resolved by now.

I know this isn't helpful but I had been having problems with wifi even back with Snow Leopard. After installing the combo updater it's finally seems to be cured.