What was found
NR 1 IAC FAILED IN FLIGHT, DU 1, 2, 3, RED X THROUGH SCREENS, NR 1 FMS INOP, NR 1 RMU STILL WORKS, NO HEADING BUG OR ALTITUDE SETTING CAPABILITY EITHER. REMOVED AND REPLACED HONEYWELL PRIMUS 2000 IC800 WITH A REPAIRED UNIT FROM HONEYWELL NR LV2R992K S/N ON : 96070577 IAW CESSNA 750 M/M 34-25-01. FUNCTION CHECKED SYSTEM IAW CESSNA 750 M/M 23-80-01. CHECKS GOOD.