What was found
CLIMBING FROM FL400 TO FL410 VNAV DISCONNECTED AND FMA DISPLAYS ARM, LNAV. ALT HOLD. A/T REMAINS ENGAGED (ARM LT ON), BUT AUTO THROTTLES ARE NON RESPONSIVE TO CLIMB AND/OR SPEED CHANGES. VNAV WILL NOT RE-ENGAGE. CRUISE ALTITUDE IN FMC SET FL410, BUT HAD TO MANUALLY OPERATE THROTTLE WHILE SWITCH REMAINS ON. GROUNDED-YES. ACCOMPLISHED DFCS BITE, REF B737-800 FIM 22-11 TASK 801 AUTOTEST PASS, FLIGHT FAULT CNL A 22-11822, CNL B 22-11822 & 22-11209. ACCOMPLISHED FIM 22-11 TASK 811, ALL TEST PASS EXCEPT FMC IN FLT FAULT ON LT & RT FMC DFCS FAULT B ON BOTH. ALL SENSORS ARE OK, REF FMC BITE FIM 34-61 TASK 801. ACCOMPLISHED B737-800 FIM 22-11 TASK 837, FCC FAILS TO ENTER TOGA. OPERATIONS CHECK NORMAL. HGS BITE LAST LEG FAULTED FCC1 INVALID, REF B737-800 AMM 34-36-00. REMOVED AND REPLACED FCC1, IAW B737-800 AMM 22-11-33. OPERATIONS CHECK NORMAL. ACCOMPLISHED SENSORS TEST OF FMC 1&2 AND OPERATIONS CHECK, REF AMM 34-61-00. ALL OPERATIONS CHECKED NORMAL.