The Broadcom Wi-Fi may be detected but if not plugging in using an
ethernet cable and getting all the updates will often being the Wi-Fi
card to life.

I have a Broadcom 4311 wireless nic in my older Gateway and the only
problem I have encountered was when I went from 10.10 to 11.04 and
installed the additional drivers for it, it quit working. I discovered
that when I removed the drivers, it worked.

I discovered pretty much the same thing. One can use

sudo modprobe -r acer-wmi

or, for a more permanent effect

cd /etc/modprobe.d
sudo gedit blacklist.conf

Insert at the end (or anywhere else) "blacklist acer-wmi" without the quotes.