There may be two problems:
1, no wireless network card driver
2, the wireless network card driver does not automatically load
Question 1: Wireless LAN Driver
Baidu the NIC driver iwlwifi-9000, as iwlwifi-9000-pu-b0-jf-b0-34.618819.0.tgz, unzip the file ".ucode" copied to the directory / lib / firmware /
Question 2: Wireless LAN Driver automatically loads
Edit or create a new file /etc/modprobe.d/ideapad_laptop.conf, reads as follows (only one line of text):
blacklist ideapad_laptop
Save, and then carry out the command "sudo / sbin / modprobe -r ideapad_laptop".
After the above two problems to solve when Ubuntu starts, the wireless card automatically available, otherwise after each launch had to manually perform a command "sudo / sbin / modprobe -r ideapad_laptop".