What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED INTO BDA DUE TO THE FLIGHT CREW REPORTING DURING DESCENT THEY LOST AUTOPILOT, AUTO THROTTLE AND CAPTAINS INSTRUMENT PANEL (NOTE: ADIRU #3 WAS ON DEFERRAL DUE TO IT BEING INOPERATIVE). THE AIRCRAFT LANDED SAFELY AT BDA AND TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE FOUND THAT #1 ADIRU HAD FAILED CAUSING THE ISSUES WITH THE AUTOPILOT, AUTO THROTTLE AND THE INSTRUMENT PANEL. MAINTENANCE REPLACED THE #1 ADIRU PER AMM 34-12-34 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.