Ubuntu – Broadcom B43 WiFi not working in Ubuntu 14.04 LTS

Type in a terminal:

sudo apt-get install b43-fwcutter

Under the desktop menu System > Administration > Hardware/Additional Drivers, the b43 drivers can be activated for use.

Restart.

Edited:

Install dkms.deb, patch.deb, fakeroot, and bcmwli. Those packages are in Ubuntu installation CD in the following paths:

/pool/main/d/dkms.deb
/pool/main/p/patch.deb
/pool/main/f/fakeroot
/pool/restricted/b/bcmwli 

Enable STA driver in additional driver.

sudo modprobe -r b43 ssb wl
sudo modprobe wl

Please hook up the ethernet and open a terminal and do:

sudo modprobe b44

Your ethernet should now be working. Now do:

sudo apt-get purge bcmwl-kernel-source
sudo apt-get install firmware-b43-installer

Detach the ethernet, reboot and both should now be working. If it is not yet working, please do:

sudo apt-get purge bcmwl-kernel-source

Reboot. If it is still not working, look for clues here:

rfkill list all
dmesg | grep -e b44 -e eth0

The driver b44 is correct for your ethernet device. Your system shouldn't hang loading the correct driver. Please run:

dmesg > wifi.txt
lsmod >> wifi.txt

Find the file wifi.txt in your user directory and transfer it on a USB drive or similar and paste it here: http://paste.ubuntu.com Give us the link in your reply.