The laptop has Ubuntu 14.04, it shows neighbors networks and it was working fine before. My phone and desktop connect to my home Wi-Fi with no problems. This has happened a few times before but in an hour or so I can resolve the problem by rebooting. It has been almost a day and it didn't fix itself.
I have tried:
sudo apt-get purge bcmwl-kernel-source sudo modprobe -rv wl sudo modprobe -v brcmsmac sudo service networking restart sudo service network-manager restart ifconfig wlan0 down ifconfig wlan0 up
iwconfig wlan0 txpower off iwconfig wlan0 txpower auto
I rebooted after those were executed but it did nothing.