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iMac 2011 - no wifi connection after sleep under Lion

since i am using osx lion, my iMac is disconnected from my wireless network after sleep. (27 inch mid 2011, i5 with 2tb and ssd) (it states, that none of my preferred connections are available). sometimes it is connected ... but internet just won`t work.

besides that wifi is working just perfectly ... no drops no instability!

i am using airport extreme with 5ghz n-network, router is about 10 meters away (full signal).


under snow leopard i didnt experience any problems ... but since lion (which i am using since GM release) its really annoying because after every sleep i need to deactivate wifi and reactivate to connect.

i tried smc and pram reset ... changed my 5ghz settings to channel 36, deleted all other networks, did a reinstall (fresh!!) ... nothing helped 😟

this is NOT an airport station issue ... my other macs and iPhone are connected just fine.


please, this is VERY annoying .... if you have any hints i would be very grateful!


with kind regards,

felix

iMac, Mac OS X (10.7)

Posted on Jul 21, 2011 1:05 AM

Reply
399 replies

Mar 10, 2012 3:38 PM in response to mhettinger

mhettinger:

Please note that you can turn off the display screen after a selected time.

User uploaded file

This setting is about 12 minutes or so. If your screen does not shut down, you

need to check the boxes appropiately. No more screen heat.

My iMac has been on continuously for more than 3 months. Very dark screen

after about 12 minutes.

Mar 10, 2012 4:57 PM in response to peregrines

After researching for several hours online, I finally called Apple Support. They were able to fix the problem almost all the way by resetting the router and Airport Express and trying various other things. One unsolveable problem is wi-fi interference with my Bluetooth keyboard and mouse. I can avoid this by using the power button to wake the iMac up from sleep. An acceptable workaround.

Mar 11, 2012 3:34 PM in response to peregrines

I am having very similar problems: iMac mid 2011, 3.4 i7, 8 GB, Lion 10.7.3


We have had this problem since we received the computer May 2011. My wife has been on the phone numerous time with Apple Care and no success, we have tried flushing all the internet connectivity information at least three different times without fix.


Even searching through this string, we have dropped our connectivity 3 times and had to re-establish. Using an Airport extreme that is about 25 feet away connected to high speed cable modem (full signal strength indicators in menu bar). We have an older 21 inch iMac, 3 MB Pros, an older Powerbook, and a Mac mini all connected to the same network and none of them have any issues anywhere within the house. With the exception of the Powerbook and 1 of the Macbook Pros, all are running Lion.


New problem identified: trying to update a 4th Gen iPod touch connected to this 27 in iMac and with connection established, I can connect via Safari to the Internet and to the iTunes Store, but it gives me an error message saying it can't connect when trying to download the iOS 5.1 update to the iPod (can do it successfully on any other Mac in the house).

Mar 11, 2012 6:02 PM in response to spinepro

Spinepro.

"...4th Gen iPod touch connected to this 27 in iMax...

Why are you connecting? it is no longer required to use iTunes. Simply plug in power from an appropriate power supply charging point, (NOT the computer), and key in update on the Touch. No other mac in the

house need be used, as well.

The update will be done wirelessly using the router, irrespective of the problems in the iMac.

Please disregard if you already know this.


iMac Problem: This MAY help, or not.

Set Screen saver to NEVER.

Set Sleep to NEVER

Set DISPLAY sleep to about 10 minutes

Set: Put hard disks to sleep when possible.

Leave it on. The screen will go dark, but the machine will come up with a mouse wiggle.

You can do back to my mac, and wake it up at any time. If you do this, does it help?

iMac 1,8, Lion.

Mar 11, 2012 6:06 PM in response to peregrines

I updated my Imac with the patch Apple released and my problem didn't go away. My Imac was dropping connections whether it slept or not. left and right....


What I did do is get rid of all my bluetooth devices. Mouse, Keyboard and trackpad. I then used an old wired keyboard and mouse and since then, over a week, the problem has not happened...


If you have a wired keyboard and mouse, try using that, make sure there are no bluetooth connections in the area like an iphone or ipad and see if the problem goes away...

Mar 11, 2012 6:21 PM in response to Nubee1

Hi. No luck.


Screen saver is NEVER. Computer sleep is NEVER.

Display is 2 minutes. or 12 or 20. It makes no difference.

The computer stays on and the screen stays on.


(Also, I may have posted this twice, but I don't see the first post.)


I guess I need to run the wire from the Airport to the computer and connect that way.

So much for wireless.

Thanks for the help.

Mar 11, 2012 7:31 PM in response to mhettinger

It might be your router. I had exactly the same problem with a MacBook Pro. In the end I disabled the wi-fi on the router, connected it to my Time Capsule, set that up as the router, and now it all works perfectly. I don't know the technical ins and outs, but it seems that there is a slight incompatibilty issue somewhere....

Mar 12, 2012 8:02 AM in response to mhettinger

Oops. The problem is not solved. The iMac and Airport only behave when the apple rep is on the line.


hmmm..


OK. The problem is related to the phone. I kid you not. As long as the phone (which works over internet) is off the hook, the Airport remains on, even if the computer is asleep. BUT (remember, the computer is asleep) as soon as I hang up the phone, the Airport router clicks off.


Calling Apple again.

Mar 12, 2012 9:02 AM in response to mhettinger

An Apple senior rep figured out how my computer was turning off the internet whenever it went to sleep, and it never was a software problem.


Putting my iMac to sleep turned off the Airport because I had the iMac plugged into an APC surge protector/power strip. The iMac was plugged into the "master" plug, which was a remnant from the old days when we wanted to power down the computer and have its peripherals power off as well. So, when the computer powered off, the APC turned off the Airport.


I have put tape over that "Master switch" and now I can set my computer to go to sleep, knowing it won't turn off the wireless.


Now, my other problem, which is why this is in this thread, was that the computer display would not sleep. I am checking that now.

Mar 16, 2012 3:42 PM in response to ivannamac

Hi ivannamac


The higher echelons have said that this form of resolution is inappropriate. The fact of it is that testing this configuration has worked in a short test for me as it has for you but this has been completely discounted by them. In the end there is only so much that can be done. But to let you know there is no fix and none proffered or on the horizon either. Mow I am convinced to spend elsewhere. Good luck to everyone seeking a resolution.

iMac 2011 - no wifi connection after sleep under Lion

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