As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLE DISENGAGES UPON THROTTLE MOVEMENT. AUTOTHROTTLE WILL ARM THROTTLE NR 2 APPEARS NOT TO MOVE AND THEN IT DISENGAGES. THRUST LEVERS WORK NORMALLY IN MANUAL FLIGHT. ACFT GROUNDED. NO FAULT ON CURRENT STATUS, SERVO TEST PASSED NUMEROUS TIMES REF AMM 22-31-00.