Raise the X axis to more than 30mm by pressing the LCD knob for longer than 3 seconds. Turn the knob to move up

Place a metallic object underneath the Pinda probe. The red light on the probe should turn off

If this test fails, do not attempt to print or use your printer. Carefully verify the wiring of your PINDA

The recent Prusa firmware allows you to check the value of the Pinda probe via the LCD menu Support -> Sensor info