2014 edit: If you’re experiencing problems on Ubuntu 14.04 with wifi on your Lenovo laptop with a Centrino wifi chipset, try disabling wireless N.
Just updated my laptop to Natty Narwhal and I may write something about it in the future (spoiler: Unity sucks). Anyway this post is just about the solution I found for the broken wireless network manager applet in Ubuntu 10.10 and 11.04 in Lenovo B450 and probably most other Lenovo laptops.
Ever since I upgraded my laptop to Maverick Meerkat, my wireless isn’t automatically enabled on startup. It was no big deal back then since I could just simply tick the Enable Wireless in the network manager applet. But when I upgraded to Natty Narwhal, my wireless was permanently disabled.
After hours of trial and error, I found out the culprit. Running
sudo rfkill list showed that I have an “acer-wireless” even though I wasn’t using an Acer machine:
bry@Abraxas:~$ sudo rfkill list 0: acer-wireless: Wireless LAN Soft blocked: yes Hard blocked: no ...
The solution to this was simple: disable it by adding
blacklist acer-wmi at the end of