At a certain point you don't like the way the touch screen of your interface is recognising your input or you tried recalibrating but misclicked and now you can't even get into the menu of the interface to choose screen calibration.
Here's a very easy solution for the Zen Tour, Goliath and Goliath HD to recall screen calibration via the hardware buttons on the device:
Zen Tour - Click and hold together the Antelope and Gain button until you see the screen calibration screen.
Goliath, Goliath HD - Click and hold together the Antelope and Mono button until you see the screen calibration screen.
If you have any further issues with you device - please get in touch with us!