As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLE KICKED OFF WHEN SELECTED TOGA ON T/O AND WOULD NOT REMAIN ENGAGED IN FLIGHT LONGER THAN A COUPLE SECONDS. GROUNDED-YES. A/T LOGGED MSG 22-31687. PERFORMED B737-800 FIM 22-32 TASK 819. A/T SYSTEM SERVO AND BITE NORMAL, OK FOR SERVICE.