What was found
AFTER TAKEOFF FROM KBAZ THE YAW DAMP AND AUTOPILOT FAILED TO ENGAGE. BOTH LEFT & RIGHT AP CHANNELS WERE ATTEMPTED WITH NO RESULTS. FLIGHT DIRECTOR FUNCTIONED NORMALLY. OPS CHECK A/P SYSTEM CHECK IS GOOD, POWER UP A/C FOR SEVERAL HRS CHECKING A/P OPS CHECK GOOD, ACCESS MAINT MODE ALL SYSTEMS PASSED. C/W GROUND MAINTENANCE TEST ON SP2-8000 SYSTEM ALL TEST PASSED, COULD NOT DUPLICATE MALFUNCTION SYSTEM, OPS CHECKS GOOD IAW 650 MM CH 34-21-01.