What was found
AUTOTHROTTLE WILL NOT ENGAGE. ACFT GROUNDED. ACFT RELEASED IAW MEL 22-4B A/T SYS INOPERATIVE. A/T INFLT REVIEW SHOWED ON 3 FLTS A TOTAL OF 54 FAULTS OF A/T ENG 28VDC INV 22-31543, SUSPECT LRU FCC-A. PERFORMED FIM 22-31, TASK 802 AND 801. A/T BITE PROCEDURE - A/T CURRENT STATUS TEST GOOD, THROTTLE MOTOR TEST GOOD. DUE TO AMOUNT OF FAULTS, R & R FCC A COMPUTER REF AMM 22-11-33. OPS CK NORMAL REF SAME MM. CORRECT SOFTWARE IPC ALREADY LOADED. GROUND VERIFICATION TEST GOOD. A/T CURRENT STATUS TEST GOOD REF AMM 22-31-00. THIS CLEARS MEL 22-4B.