06-10-2014 06:39 PM - edited 06-10-2014 06:50 PM
I do not have this device, but I will offer what has worked on my Yoga 2 Pro. First and simplest, I assume you have checked Fn F9 (I think it is F9, but I do not have my Y2P with me right now; the proper F key has a picture of a touchpad with a line through it). This toggles the touchpad. A couple of times I have somehow accidentally toggled my touchpad off. I do not know how, but it definitely was NOT by accidentally using Fn F9. I think this key combination is pretty standard on Lenovo devices.
Second thing is, that after a Windows 8.1 update my touchpad stopped working. I already had the latest driver, but Iuninstalled the driver, restarted, re-installed the same driver, and everything was fine. When you re-start you will have touchpad functionality, but it will be slow until you re-install the proper driver. If you have an external mouse, that would be handy.
Hope this helps.