As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLE ARM SWITCH DOES NOT STAY IN ARMED POSITION. ACFT GROUNDED. CONFIRMED FAULT DURING SERVO MOTOR TEST FAULTED SERVO NR 1 MSG22-31780. REPLACED AUTOTHROTTLE SERVO MOTOR WITH SERVICEABLE ONE. ACCOMPLISHED SERVO MOTOR INST TEST, TEST PASSES REF MM 22-31-91-400-801.