If you're using Broadcom BCM4312 (full name: "Broadcom Corporation BCM4312 802.11b/g LP-PHY (rev 01)") same as mine, then you probably could easily fix by installing the following:
sudo apt-get install firmware-b43-installer b43-fwcutter
or try another one if the above doesn't work:
sudo apt-get install broadcom-sta-commonYou're adviced to reboot your system, but before that you may try:
- off & on your wireless device, it may work straight away without system reboot.
- run command modprobe b43
If you choose to reboot and the wireless device doesn't start, try modprobe b43. To autoload the device at startup, edit /etc/modules, add "b43" to the list. That should load it during startup.