What was found
AIRCRAFT NOT GROUNDED: STAB OUT OF TRIM ILLUMINATED AT LEVEL OFF FL350 WITH A A/P ENGAGED WITOUT WARNING AIRCRAFT PITCHED DOWN AGGRESSIVELY WEN 800 FEET DOWN AUTO PILOT AND AUTO THROTTLE WERE MANUALLY DISENGAGED USING TRIM SWITCH ON YOKE A/C RETURNED TO PROPER TRIM AS PER QRH AUTO PILOT AND A/T NOT USED FOR REMAINDER OF FLIGHT. MEL 22-01A. ***SUPPLEMENTAL ACTION SECT. 4 AND 5: REMOVED AND REPLACED FCC CH A ( #1) IAW AMM 22-11-33 PERFORMED LAND VERIFIED TEST IAW AMM 22-11-00-700-801.***(CLOSED)