What was found
IC-600 1 FAILED INFLIGHT. NO IC-600 BUS FAIL EICAS MSG, BUT CAPTAIN'S PFD & MFD HAD RED X'S. SELECTED SG ON REVERSIONARY PANEL & BOTH PFD & MFD WENT BLANK. AHRS 1 FAILED INFLIGHT. SPS ADVANCED CAUTION MSG INFLIGHT. AUTO PILOT FAILED INFLIGHT. YAW DAMPENER FAIL INFLIGHT. R & R AHRS COMPUTER NR 1 IAW AMM 34-21-01. AHRS OPERATION IS GOOD IAW AMM 34-21-00. PERFORMED EFIS OPERATION IAW AMM 34-22-00. OPERATIONS CHECKED GOOD. STALL PROTECTION SYS OPERATIONS IS GOOD IAW AMM 27-36-00. AUTO PILOT & YAW DAMPENER SYS OPERATION IS GOOD IAW AMM 22-11-00.