What was found
MIA - FLT 973 - EN ROUTE MIA-GIG, AT CRUISE, APPROXIMATELY 2 HOURS INTO FLIGHT, THE EICAS MESSAGE 'SPOILERS' AND 'R YAW DAMPER' ILLUMINATED. AT THE SAME TIME THE EICAS MESSAGE 'AILERON LOCKOUT' WAS FLICKERING AND THEN BECAME A STEADY MESSAGE, MOMENTS LATER THE RUDDER RATION EICAS MESSAGE ILLUMINATED. CIRCUIT BREAKERS WERE NORMAL, AS WELL AS, HYDRAULICS AND ELECTRONICS. RETURNED AND LANDED MIA W/O INCIDENT. REPLACED BOTH RIGHT CSEU UNITS AS A PRECAUTION. LAND 40 TEST PASSES WITH NO FAULTS. NO FAULTS ON GROUND TEST. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)