Wifi hard blocked

I have just installed Ubuntu 14.04.2 LTS on my Lenovo-G50-30 laptop, replacing Windows 8. 'Enable wifi' is greyed out. Typing rfkill list all in the terminal tells me that

0: ideapad_wlan: Wireless LAN
Soft blocked: no
Hard blocked: yes
and
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no

So the problem is presumably that ideapad_wlan is hard blocked. 'sudo rfkill unblock all' doesn't change this. There seems to be no switch on the laptop itself, nor are any of the F keys relevant.

How do I enable WiFi?

Sometimes this can be fixed by blacklisting the ideapad_laptop module with echo "blacklist ideapad_laptop" | sudo tee /etc/modprobe.d/ideapad.conf and rebooting If it doesn't work the blacklist can be removed with sudo rm /etc/modprobe.d/ideapad.conf There is a fix being worked on and addition models being added and some models are fixed in the Utopic 3.16.0-30 kernel

Dmitry Tunin has made a kernel with the fix if you want to try it, a link from the bug report https://bugs.launchpad.net/ubuntu/+source/linux-lts-utopic/+bug/1397021/comments/6