If my (failing) memory is correct. You touch anywhere on the screen while it is powering up. That should get you into touchscreen calibration mode. It has been many years since I've worked on these, so I could be completely wrong.
Official MedWrench Guru
If attempting to calibrate the user console, you should be able to access calibrations via settings. If however you are attempting to calibrate the head, there is a calibrations dongle which must be plugged into the power box to enter the head's calibrations mode. If you need more assitance in this procedure or identifying the dongle, please feel free to reach out to our techncial support line at 888-667-1062 or emaling at firstname.lastname@example.org
Ryan Clarke - ISS | We Are ISS | 888-667-1062