If the touch is working on your on board Android but not on your PC or MAC, you have probably mixed up the cables. What we mean by this is that you cannot have say a HDMI coming form the rear of the LED and then the USB for Touch connected to the front of the LED. You need to have both cables coming from the same location as the inputs are paired.

So, your USB and HDMI both have to come from either the front of the LED or the Rear. Please note on the Rear, there are additional inputs underneath the LED as shown in the Image below.