For aircraft with Avidyne PFD EXP5000 installed and the aircraft is on the ground, if the PFD after booting up continues to show red X's in the AirData (top portion) section of the PFD and does not go away;  IAS (Indicated Airspeed), Vertical Speed (VS), Altitude.

Pilots are required to take the plane to an Avionics Shop for further troubleshooting, and possible return of the unit for service.