The keys on the touchscreen do not work
Remedy:
-  Clean the surface with a moist cloth. Check also for scratches or damages.
 -  Check if the frame presses on the touchscreen. The active surface is bigger than the screen.
If necessary bring some clearance between the frame and the touch.
 - If you tip simultaneously on two spots, the touchscreen can block for a short period.
Wait for a couple of seconds. 
		