[email protected]:~$ rfkill list

 1: phy0: Wireless LAN

     Soft blocked: no

     Hard blocked: no

 2: acer-wireless: Wireless LAN

     Soft blocked: yes

     Hard blocked: no

 3: tpacpi_bluetooth_sw: Bluetooth

     Soft blocked: yes

     Hard blocked: no

解除安裝acer-wireless。。

sudo rmmod -f acer-wmi

sudo rfkill unblock all

rfkill list all

解除安裝後，無線訊號就可以找到。

sudo echo "blacklist acer-wmi" >> /etc/modprobe.d/blacklist.conf

新增黑名單。

sudo gedit /etc/rc.local
把rfkill unblock all新增在exit 0這一行之前。
OK，搞定。