What was found
SAS A/P CUT FAILURE; YAW SAS AND BACKUP SAS ACTUATOR FAILURE DURING START RUNUP. A TEST FLIGHT EVAL FOUND DURING AUTOPILOT TEST YAW SAS AND BACKUP SAS CAUTION LIGHTS ILLUMINATE AND REMAIN ON. WHEN CAUTION IS ACKNOWLEDGED AP TEST PASS IS ILLUMINATED IN GREEN ON CAD. DURING SAS/AP CUT FROM EITHER SEAT APPROPRIATE OFF LIGHTS COME ON, HOWEVER, BACK UP SAS AND YAW SAS ILLUMINATE IMMEDIATELY INSTEAD OF THE NORMAL 3-5 SECOND DELAY. AP SYSTEM CANNOT BE BUILT BACK UP. NO AFCS SUBSYSTEM CODES ILLUMINATE FOR FAILURE. REMOVED AND REPLACED SEMA ACTUATOR IAW AMM 67-20-00, 4-14.