What was found
AIR RETURN/ EMERGENCY DECLARED. AVIONICS SMOKE LIGHT WITH INDICATION OF SMOKE ODOR IN COCKPIT AT 9000 FT AFTER AUTOPILOT ENGAGED. COMPLETED SMOKE DETECTION SYSTEM CHECK IAW AMM 26-13-00-05, SYSTEM CHECK AGAIN. INSPECTED AVIONICS BAY, NO FAULTS FOUND. GROUND OPS CHECK OF AVIONICS SYSTEM, OK. COULD NOT DUPLICATE LIGHT OR SMELL. (K)