Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action; General Release Refused / Aircraft Not Accepted
Aircraft; Environment - Non Weather Related
During Preflight flow was unable to select terrain display.  Contacted Maintenance Control and was instructed to check reset several circut breakers.  No success.  Wrote up discrepancy in logbook.  Local Maintenance was notified and arrived.  Was informed by ground crew chief that this had been a recurring problem on other aircraft type Flights.  Was informed of note regarding this situation.  The NOTAM FAI 04/431 indicated there was problems due to GPS interference testing from 30April 21 to 15May21.  It was now [after those dates].  Maintenance was unable to make repairs.  Dispatch requested we push off gate with revenue.  I declined.  Off loaded passengers.  Was asked if I was willing to taxi aircraft without passengers to see if problem would clear.  I agreed in accordance with FOM.  Asked dispatch what flight number would be.  He indicated it would be XXXX.  We pushed off gate and taxied south and continued northbound on runway.  Maintenance was observing operation.  We tried many attempts to engage terrain display without success.  Parked airplane on hardstand.  Secured Airplane. Was not sure if failure of terrain display was system failure or continued interference testing.  If testing was indeed taking place after the NOTAM effective dates; they should be updated.
Air carrier Captain reported a system malfunction during pre-flight that may have been caused by GPS interference testing.