My Lenovo G480 does not detect my wireless network when I'm running Ubuntu, but it has no problem in Windows 7. When I boot with Ubuntu, it immediately displays a message saying "You are disconnected." and when I try to check for wireless networks, it doesn't display anything.
While I don't have this particular model laptop, I did a little research and found the following Link to UbuntuForums I have listed the relevant commands below....
Connect to the internet using a wired connection. Type the following to get to a terminal CRTL T (hold down the ctrl key and hit t) copy/paste the commands, one line at a time into the terminal window. reboot and try a WIFI connection.