Wifi won't turn on since upgrade to Lion

I didn't expect that to fix your Wi-Fi issues. I would focus on your network and try resetting/recreating it from there (i.e. modem/router/network in system preferences).

Well yes, sometimes it does work to just search for my network again. Like it did now and at the moment I'm on my Wi-Fi connection, but it doesn't work all the time. It's realy strange ... And when I reboot it won't have WI-Fi anymore.

Plus I already checked with my provider and normally there is nothing wrong with the modem or the connection. In the advanced settings off the network preferences I also tried some stuff I found on the internet. But it's always a solution for a short periode.

Again, I am not sure what about Lion is causing your issues when I have none and I am using the same OS and have the same hardware as you, which is why I am saying it is most likely something other than Lion that is causing you to have problems.

How did you install Lion?

By doing a clean install do you mean you erased your hard drive and then installed just Lion on it?

If so, then that is most likely why you are probably having issues, as Lion isn't intended to be a stand alone OS. Meaning it is intended to upgrade from v10.6.8. Even though you can install Lion on it's own it does leave out a lot of files that would normally be there if you installed it on top of v10.6.8.

I would bet that the majority of issues that people are having are due because they didn't install Lion on top of v10.6.8. I do know that I have installed lion on my MBP 5,3 on top of v10.6.8 and have had no issues, but I did install it on my older MBP by it's self and although I have no Wi-Fi issues I did have some differences when compared to the other install.

So you are still having Wi-Fi problems with your SL > Lion upgrade? Did you happen to make sure you updated SL fully before installing Lion? When you reinstalled SL did you happen to reset your network?

Yes, reinstall SL > Update completely > reset your Network completely by removing your network from Network Preferences and reset both your modem and router and set up a new network. Once you have established a new functional network, then upgrade to Lion.

When upgrading to Lion try this:

Once you have the Lion OS X Install App on your system right click on the file and select 'Show Package Contents' then click on the 'Contents' folder. Find the 'InstallESD.dmg' file and drag it to your desktop. Once this file is on your desktop make sure you don't have anything opened or running. Double click on the 'InstallESD.dmg' file, which will mount the installer, then double click the Install Lion Icon and follow the directions that follow. This should install Lion and then after the install make sure you run an update again. After this you should not have any issues hopefully.

Thank you and good luck!

happened to me. I went into the system preferences folder and deleted all the plist that did not say "orig" on the end, and then changed those to just plist. My network preferences pane is back now at least, upon restart.

None of these issues are going to resolve the problem. It is most likely a driver or firmware problem with our broadcom wireless chips.

The fact of the matter is that the majority of us ARE having trouble with Lion and late 2008 Macbook Pros and NONE of us had trouble with 10.6.8 (which by the way, you have to have in order to install Lion which you questioned earlier). When reverting back to 10.6.8 and using the same configurations from our routers/network setups, we are able to turn WiFi on without any problem.

It is clearly an issue with Lion. If you indeed have the same exact hardware, then you are an exception within this thread.

By the way, a friend uploaded his System Configuration folder to me so that I might replace my folder with his. He is currently running a 2010 Macbook Pro and Lion and having no trouble at all. When I replaced my System Configuration folder with his and rebooted, my WiFi comes back immediately and asks me to select a network and I can connect fine. For now, this seems to be working with no ill effects.

This also leads me to believe it's a problem with the driver/firmware of the wireless chips.