Works fine with the latest Ubuntu. I found this on another search:
The Broadcom wifi chipset requires a proprietary driver to work.
Run these commands to install and enable it.
sudo apt-get install bcmwl-kernel-source sudo modprobe -r ideapad_laptop
But no joy- no wifi.
lsusb says broadcom BCM2045B (BCD-2.1)
Where can I find driver?