RT-AC68U Fan selection

I was inspired by this post 337 to install a fan:

http://www.snbforums.com/threads/overclocking-rt-ac56u.12578/page-17



I'd like to do something similar with perhaps 2 fans on an RT-AC68U. This does not use a USB port (very desirable feature), so hopefully someone has done this already. It's not clear what the voltage is available inside, but the power supply is 19V. There must be a 5V node for the USB. Can anyone confirm if there...

RT-AC68U Fan selection