What was found
ON CLIMBOUT ELECTRICAL SYSTEM STARTED TO "FADE" IN AND OUT. SEEMED TO BE THE LT SIDE ELECTRICAL, AUTOPILOTS AND AUTO THROTTLES BECAME INTERMITTENT. WHEN A/P WOULD BE WORKING IT HAD A PRONOUNCED BUMP IN PITCH LIKE AIR IN HYD SYS. CAPT'S FMC TIMED OUT AND WOULD NOT RECOVER. EICAS'S WENT BLACK. GOT AUTO PILOT DISCONNECT WARNING WITH A/P DISCONNECTED AND HAND FLYING. REMOVED AND REPLACED LT GCU, OPS CHECKED IAW MM 24-22-02-4. OPS CHECK GOOD. RAN LT ENG IAW JRH CHAPTERS 5 AND 6 WITH ENGINE RUNNING, ISOLATED SHIPS POWER TO LT GENERATOR, FREQS AND VOLTS WITHIN LIMITS IAW MM 24-00-00-0.