Do you have the machine in eco mode? Just touch the eco button and the machine should become active again. Try switching the machine off and on again and that may cure it.
Occasionally we can 'freeze' the screen by touching several areas together, a bump in transit, or most commonly going into settings and not realising you have calibrated the screen, are all reasons for the screen to freeze.
If this has happened you will need to follow these instructions:
Switch off the power to your machine.
Switch the machine on, at the same time keep the two needle position buttons pressed and wait for the machine to start up. until the calibrate screen appears.
Using your stylus touch each of the cross hairs as accurately as you can.
You screen is now working again.