JMGO V8 Quick User Manual page 23

Video Signal Source Switching
When external signal source is imported through HDMI port into the device, the user can
enter the signal source setting interface by either calling out the shortcut menu upon
tapping the "JMGO" button or clicking on the "Signal Source" button on the desktop. At
the signal source setting interface, choose the favorable signal source, then the external
video source will be displayed through the device onto the screen.