Turn the DAC off from the master switch in the back panel. Let the unit discharge for 10-20 seconds. Then turn the unit on while holding down the PS Audio blue button on the top left corner of the front panel. This should bring the unit to a screen calibration.
You will have to touch each of the four corners in numerical sequence. Use a small object like the eraser on a pencil for best results. Do not use anything sharp on the touch screen.
Once the calibration process is finished the unit will restart.