As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOTHROTTLES WILL NOT REMAIN ENGAGED. WILL MOMENTARILY ENGAGE, BUT KICKS OFF AFTER 3-5 SECONDS. GROUNDED - YES. INTERROGATED FMC, FOUND MULTIPLE FAULTS FOR ASM 1. REMOVED AND REPLACED AUTOTHROTTLE SERVO MOTOR, IAW B737-800 AMM 22-31-91/401. GROUND VERIFICATION TEST IS GOOD.