The key to finding the correct driver for any network card is what is known as the PCI ID (PCI.ID). There are dozens of Broadcom wireless cards and more seem to appear every day. Knowing what Broadcom Wireless Card you have So with that in mind, the following is what we have right now which is simplified in just 3 steps: 1.

Link 3 - Gives an error similar to 'Sorry, installation of this driver failed.' More problems found in Launchpad, Ubuntu Forum and Askubuntu.Wireless card does not turn on, enable or disable (Link 2 Below).After upgrading from a previous version (eg: 12.04 to 12.10) it stops working.Tries to connect many times without correctly finishing connection.

Appears connected on Network Manager but does not receive Internet.

Connects and disconnects continuously every X amount of seconds.

Fails when installed via Additional Drivers / Additional Hardware (Link 3 Below).

Creates huge log reports trying to correctly configure or connect.

System freezes completely (You can only press Reboot/Power button) (Link 1 Below).

Crashes system with dmesg errors in log (Link 1 Below).

Stops any receiving/transmitting traffic (Needs reboot to temporarily fix).

Keeps asking for password even on cases where AP does not have any.

Stops searching for other devices (Does not see any other device).

Connections timeout after several minutes or hours.

Common problems that will be solved (Apart from drivers not installing) are: After you follow this guide, you will NEED to test your wireless connection for at least 2 hours (I actually recommend 8 hours) with another device in either Ad-Hoc Mode, Infrastructure Mode or Both. In total we wanted to offer an answer that could be easy to follow and covered most Broadcom Cards / Drivers. Special thanks to chili555 who helped in the Ubuntu forums and on this site with many questions related to Wireless devices and to others who have contributed through E-Mail, chats, IRC and more in testing various drivers with several of the most popular Broadcom Wireless cards (Huge Thanks to Chili555 really. This answer is based on an extensive research done by various Ubuntu users that worked together in almost all issues related to Broadcom.

Broadcom 20702 driver says not detected