F123 Series 3D Printers Touchscreen Calibration
At some point you may need to calibrate the touchscreen on your F123 Series Printer. It is recommended that you use a stylus for this procedure or a pencil eraser if a stylus is not available. Extreme care should be taken when running the calibration as it could cause button inaccuracies and may make the panel unusable. However, there is a way to recover from this.
Source-Computer Aided technology Blog.