Ubuntu – wireless bcm4318 not working

Edit: I researched also link suggested above – it is option (3) And indeed is very helpful. Especially @LuisAlvarado's answer – it contains table which suggest using linux-firmware-nonfree – I tried and it did not worked (possibly because my system was polluted by remnants of previous attempts). Instead, b43-fwcutter from option (2) after clean reinstall worked for me. Linked answer contains good explanation of the process, but advice about exact module to use might be incorrect. wileress.kernel.org has different value value, which worked for me.

Original post:

I cannot get bcm4318 working on Lubuntu 14.4.
This card worked on lubuntu 12.10 but upgrading failed, and after full reinstall from liveUSB I cannot get wifi to work. I tried these suggestions:

• (1) Advice for 12.4 suggests to apt-get --reinstall install bcmwl-kernel-source
• (2) This says: apt-get purge bcmwl-kernel-sourceinstead, says: apt-get install b43-fwcutter firmware-b43-installer but did not work either.
• (3) This suggests apt-get install linux-firmware-nonfree – well worth reading, excellent explanation of problem.

Every time I purged packages from previous try and rebooted afterwards.

• (4) This also suggest blacklisting some entries. It seems that b43 from (2) should work (bcm43xx entry is blacklisted). But no luck.

• (5) Downgrading is also suggested by this year-old answer but I was hoping there is something newer/better. The author claims that every release makes bcm43xx harder.

What else I should try?

I checked "ultimate authority" on bcm43xx wireless, http://wireless.kernel.org/en/users/Drivers/b43#Supported_devices which says (in debian section) to use option (2), but no luck.

By "no luck" I mean that iwconfig says no wireless connection.
In my office I have wired connection to modem but no apparent wireless.
Is iwconfig a right way to test if my wireless is alive?

lsmod | grep -e b43 -e wl:

b43                   356470  0   
bcma                   42043  1 b43  
mac80211              545990  1 b43  
cfg80211              409394  2 b43,mac80211  
ssb                    51854  2 b43,b44  

lspci -nn | grep 0280

06:02.0 Network controller [0280]: Broadcom Corporation BCM4318 [AirForce One 54g]   802.11g Wireless LAN Controller [14e4:4318] (rev 02)  

uname -mr

3.13.0-24-generic i686  

My laptop is Acer Aspire 5610Z with 0.5GB of RAM which I am going to upgrade to 4GB ASAP.

I got it working.

Correct answer is option (2), at least for my combinations of whatever is relevant.

What probably caused my earlier problems was that I was installing using synaptic gui. When I did install using terminal and apt-get, I noticed that apt-get update complained about duplicate sources. Once resolved, I again went over whole installing exercise, including fresh reinstall (to make sure there are no remnants of other installs), and straight to option (2) as suggested by wireless.kernel.org.

Regarding other options, it is above my paygrade to decide if they are invalid and need to be updated, or can stay as is, if approaches suggested by (1) and (3) are correct and may work for someone else.