What was found
DURING CRUISE BOTH GLOBAL POSITIONING SYSTEM UNITS FAILED. ACCOMPLISHED RESET OF MULTI MODE RECEIVERS. BOTH UNITS CAME BACK ON BUT THEN FAILED AGAIN. EMERGENCY DECLARED. LANDING UNEVENTFUL. AIRCRAFT WAS GROUNDED. MAINTENANCE FOUND CENTER ILS MULTI MODE RECEIVER INOPERATIVE. REMOVED AND REPLACED THE RECIEVER IAW AMM 34-21-01. ACCOMPLISHED LEFT AND RIGHT AIMS RESET. REMOVED AND REPLACED LEFT AND RIGHT GPS ANTENNAS IAW AMM 34-58-02.