MBA can't find preferred network after sleep mode

Thank you very much. This solved my problem, for now. I'm hoping it holds..

Having the same problem with a three-day-old MacBook Air (running 10.7). Doesn't seem to be an issue with the router/modem (a Thompson TG585 v8); the Air connects fine to this network immediately on reboot.

Steps attempted:

1. Updated the firmware from the Apple site. No dice.

2. Steps suggested by MeltingSnowTime: did not solve the problem.

3. In fact, after erasing the network from the keychain and the Preferred Networks, I *still* got an 'Invalid Password' message on entering the correct password, every time. After reboot, the password for the no-longer-remembered network works fine once again. Until sleep, when the problem reappears. Only I've found to reconnect is a reboot.

Do I really need to reset the PRAM on a three-day-old machine?

(This kind of bizarre problem reminds me of the heady old days of "Self-assigned IP address" on my old MacBook Pro, which as I recall never received any kind of answer from the Apple folks either... presumably they don't even look at these forums?)

Further observations:

1. In Lion, the login screen shows the Airport/wifi signal icon. When I wake my machine up from sleep when it has been connected to the network, that icon goes from the pale (disconnected) state to the dark (connected) state, just briefly, and then returns to the pale (disconnected) state again and stays there (and then as noted above, connecting to the network becomes impossible until reboot).

2. An old MacBook Pro that I've got here running 10.6.8 also has trouble connecting to the same network after sleep, but turning Airport off and back on again solves it. Not so for the new MBA.

3. Turning Wifi off before putting the machine to sleep and back on after waking also prevents the problem from happening. Seems to be triggered specifically by the machine's going to sleep while connected to the network.

Anyone get what's going on here?

I had the same problem as human_dude - turning off bluetooth solved it.

Bluetooth's never been on on the MBA, and not for months if not years on the MBP, certainly never on this brand-new network.

Simon Catton wrote:

Hi
Not sure if this is a MacBook Air problem, but I can't connect to my preferred wireless network when 'waking-up' from sleep. Will connect automatically on restart.

First, check that your preferred wireless is on top of the "known networks" list in the system settings and uncheck "Ask to join new networks"

According to Apple's support hotline info, eventually delete some files on the Mac because some configuration files may get damaged or corrupt by time, after updates or upgrades and should get deleted occasionally.

Switch off wifi on the Mac.

Delete obsolete networks (SSID's) from the "known networks" list.

Then go on and delete the files mentioned below.

You will find the files on your system drive (not your home folder) as follow:

(If you are using Lion, the Library is hidden. You have to use (menu bar) "go to" -> "go to folder" on finder to access them.)

/library/preferences/com.apple.preferences.accounts.plist

/library/preferences/com.apple.preferences.sharing.plist

/library/preferences/SstemConfiguration/preferences.plist

/library/preferences/SstemConfiguration/com.apple.airport.preferences.plist

If there are files in this folders with the same name but additional .orig at the end, delete them too.

It is possible that not all mentioned files are found on your system. That will be ok.

The files will get newly created by system on reboot.

For that reboot the machine.

Join your wireless again.

Lupunus

Thanks, Lupunus, for this suggestion. I tried following these steps precisely (I also deleted the relevant network from the list for good measure), and what happened was that after that first reboot, I got an 'Invalid password' message starting with the first time I tried to connect to the network. I had checked "Remember this network," and after reboot it connected automatically. However, putting it to sleep caused it to lose the connection and begin giving 'Invalid password' messages until reboot.

As suggested by someone above, turning off security completely does prevent this problem from arising; but obviously I can't count on being able to do that everywhere.

I also tried the suggestion in this post in a popular thread on general wifi connectivity problems with the MBA; didn't work.

This is obviously a problem with my brand-new MBA itself; going to sleep causes some problem with its provision of the password to the router. Otherwise, why would its going to sleep while connected to the network lead to failure to connect and 'Invalid password' messages with the correct password 100% of the time, while booting anew leads to flawless and automatic reconnection also 100% of the time?

I've wasted enough hours on this today already. I'm going to call Apple support tomorrow and open a case number with it. I encourage anyone else having this problem to do the same. They presumably have to be harassed directly before doing something about an issue like this.

Just to let you guys know that 10.7.2 didn't solve the problem. After sleep and wake-up wifi won't autoconnect.

I don't use any wifi security and encrryption such as WEP, WPA etc. (Using MAC address filering on wireless router only).

Not to say that other home devices do connect to my wifi access point without any problem.

The best solution so far that worked for me - is to replace wifi kernel extensions with those from 10.6.4, how-to is here: http://thoughts.maayank.com/2011/08/wireless-problems-with-macbook-air-and.html

I would note, however, that after clearing up PRAM, system controller and all the usual staff (deleting and re-adding preferred network, clearing system preferences etc.) Apple support suggested the problem is in some incompatibility with wifi access point (I use asus RT-N16).

To check this, I started wifi hotspot application on my phone and macbook connected to it after awake for several times, instantly and with no problem, so that "incompatibility" maybe really takes place.

Yes, turning off bluetooth works for me.

But I hope Apple can fix this, because in my opinion this is only a temporary solution, because the MacBook air is a brandnew machine.

I don't think that this problem is an hardware issue, because my old macbook white (2007) has the same problem.

I have updated from 10.6.8 to Lion - and now this old macbook has the same issue (after standby no automatically connection of WiFi).

So it seems, that Lion causes the problem.

For the moment the solution of turning bluetooth off works for me.

If I have to use the Magic Mouse and the BT-keyboard, I turn wifi on.

Strangly, if I have turnded on both devices (BT Mouse and Keyboard), the automatically connection of Wifi after standby works.

But If I turn both devices off, and I keep bluetooth on the MacBook Air switched on, resuming to the WiFi-netwoirk does not work.

I also have to add, that you can check if WiFi works.

You can start the MacBook Air, and after start-procedure the login-screen of Lion appears.

So, and if WiFi doesn't work properly, the Wifi-Symbol (AirPort-Symbol) is idle (light-grey).

But if I turn bluetooth off, and start the MacBook Air again, I have full-WLan already if the login-screen appears (symbol of airport is black and bold).

And I have also already access to the WiFi-netzwork, of I have bluetooth turned on, and I use the magic-Mouse and the keyboard. But if I use only the magic-mouse, I have Wifi-trouble, too.

So far...

I didn't try any of the firmware updates or file removals as mentioned above, I simply turned off Bluetooth and voila Wifi works as advertised. I really think this is a OS issue as I never had Wifi problems under Snow Leopard.

By the way this happens only on my MacBook Pro, I never have the issue with my iMac Late 2008 running Lion. I retract my OS blame earlier 😝

After trying *everything* in my troubleshooting bag of tricks (including three trips to the Genius Bar), I finally broke down and did a clean install (not a reinstall). I created at lion recovery "disk" on a USB flash drive. Restarted from that and completely wiped my internal SSD drive using Disk Utility.

I then installed Lion to the erased internal SSD.

I used my Time Machine backup to restore my user account and applications ... and nothing else.

After 24-hours, I have not seen the problem crop up.

Crud. I spoke too soon. The problem took an additional day to rear back up. No solution here.

Same problem for my new iMac, following same steps and resolved in a minute.

Thank you so much, MeltingSnowtime

I, too, followed the steps suggested by MeltingSnowTime and seems to have solved the problem for me as well. Maybe the solution is just putting the home router up to the top of the list (it was way down a long list)? And I also deleted a number of access points that have accumulated over the year (foreign airports; hotels I will not likely be in again anytime soon, etc.), and maybe reducing the number of waypoints helped. Regardless, thanks MST as your suggestion seems to have solved the problem.