This happens even with one monitor on Thinkpad T470.
I have setup my external monitor to be only display. If I simply disconnect the monitor, the laptop screen goes blank(black). If my monitor loses power supply first(if I switch it off) and then unplug it, the laptop screen picks up being main display.
This happens even with one monitor on Thinkpad T470.
I have setup my external monitor to be only display. If I simply disconnect the monitor, the laptop screen goes blank(black). If my monitor loses power supply first(if I switch it off) and then unplug it, the laptop screen picks up being main display.