What was found
WITH AUTOTHROTTLE SYSTEM TURNED OFF AT THE GATE WE NOTICED A/T MOTION OF THE MOTOR. ALSO EXPERIENCED A SURGING OF THE A/T FOR ABOUT 10 SECONDS DURING LEVEL OFF AT ABOUT 12,000'. NO MOTION OF ACTUAL THROTTLES OTHER THAN FEELING THE A/T SYSTEM PULSING CAUSING A SLIGHT WIGGLE OF THE THROTTLE LEVERS. GROUNDED - YES. ISSUE AT GATE WAS DUE TO TECHNICIAN RESETING SPEED BREAK AUTOSTOW ACTUATOR AS PART OF OVER NIGHT MAINTENANCE. FOR INFLIGHT FAULTS, REMOVED AND REPLACED FCC-A IAW B737-900 AMM 22-11-33-000-801 AND AMM 22-11-33-400-801, OPS CHECK GOOD. LLM MAINTNENACE TEST GOOD IAW DFCS LRU REPLACEMENT TEST FOR DFCS/AT GROUP #49 - AMM 22-11-00/201.