What was found
ON T/O AUTOTHROTTLES WOULD NOT ENGAGE. AUTOTHROTTLES WERE ARMED BUT AS SOON AS TOGA WAS PUSHED, A/T'S DISCONNECTED. CONTINUES T/O SETTING THRUST MANUALLY. FOUND AUTOTHROTTLE DC1 C/B POPPED. CONSULTED WITH MX CONTROL, DISPATCH AND FOFO. ELECTED TO RESET C/B. C/B RESET AND AUTOTHROTTLES ENGAGED. OPS NORMAL REMAINDER OF FLIGHT. GROUNDED - YES. CHECKED AUTOTHROTTLE DC CIRCUIT BREAKER PER AMM 20-60-01-860-801 - NO DEFECT NOTED. AUTOTHROTTLE BITE PER FIM 22-31-TASK 801 SHOWED ONLY FAULT 22-31263 "A/T 28VDC PWR INV". ACCOMPLISHED T/S FOR FAULT 22-31263 PER FIM 22-31 TASK 810 - INITIAL EVALUATION (CURRENT STATUS TEST) DID NOT CONFIRM FAULT. PERFORMED AUTOTHROTTLE OPERATIONAL TEST PER AMM 22-31-00-710-802 - ALL TESTS PASS.