Ubuntu – Dell Vostro 1520 wifi not working with Ubuntu 12.04

I got it working, same model, on linux mint 13 64-bit, which is based off of ubuntu 12.04. Assuming your laptop came with the same hardware configuration:

Do a lspci -nn | grep Network, and if you get the following: 01:00.0 Network controller [0280]: Broadcom Corporation Device [14e4:4365] (rev 01) then my solution may work for you.

There's a related question on here, How do I install BCM43142 wireless drivers for Dell Vostro 3460/3560?. The steps described there may work for you. It didn't quite work for me, I didn't know what to do after installing the .deb package.

The following driver did work for me: http://jas.gemnetworks.com/wireless-bcm43142/

He has apt sources to make it easy to install (as found at the root of that site):

wget http://jas.gemnetworks.com/jasmineaura.gpg.key -O- | sudo apt-key add -

The sources are:

deb http://jas.gemnetworks.com/debian debian main  
deb-src http://jas.gemnetworks.com/debian debian main

Then, just:

sudo apt-get update  
sudo apt-get install wireless-bcm43142-dkms

The package also removes the conflicting packages from the old proprietary drivers that don't work, which I believe was what caused me problems when I tried to use the deb package in the question linked above.

Please note this:

[    3.205709] iwlwifi 0000:00:14.3: Failed to start RT ucode: -110 
[    3.205711] iwlwifi 0000:00:14.3: Firmware not running - cannot dump error 
[    3.217939] iwlwifi 0000:00:14.3: Failed to run INIT ucode:-110

There are several bug reorts that reference this exact sequence. The first that suggests a fix is this: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1867026 It suggests renaming the firmware file that loads. Please try:

sudo rmmod iwlmvm
sudo rmmod iwlwifi
sudo cp /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode{,.bak}
sudo cp /lib/firmware/iwlwifi-QuZ-a0-jf-b0-48.ucode /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode
sudo modprobe iwlwifi

If this is ineffective, then revert the rename:

sudo rmmod iwlmvm
sudo rmmod iwlwifi
sudo mv /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode{,.bak} /lib/firmware/iwlwifi-Qu-b0-jf-b0-48.ucode
sudo cp /lib/firmware/iwlwifi-Qu-a0-jf-b0-48.ucode /lib/firmware/iwlwifi-Quz-b0-jf-b0-48.ucode
sudo modprobe iwlwifi

Then try the solution here: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1867026/comments/2

Download all the deb files to your desktop. Then install them with:

cd ~/Desktop
sudo dpkg -i linux*.deb

Reboot.