What was found
EMER PWR ON ALERT ON T/O QRH COMPLIED WITH ; NO EFFECT. MFD'S 1-3 CONTINUALLY FLASHING. ADG DEPLOYED. SHGN 12MAR19 06:15 LAX PREFORMED EMERGENCY POWER TEST PER AMM 24-24-00-5. NO FAULTS FOUND. PREFORMED BATTERY CHARGER TEST PER AMM 24-34-03-5. NO FAULTS FOUND.PREFORMED BATTERY OFF INDICATION TEST PER AMM 24-34-00-5. NO FAULTS FOUND. PREFORMED DC BUS TIE RELAY SENSING TEST PER AMM 24-32-00-5. NO FAULTS FOUND. SHGN 12MAR19 06:40 LAX REPLACED EPCU PER MM 24-08-01-4, RTS TEST GOOD WITH NO FAULTS. REMOVED AND REPLACED THE GROUND SERVICE RELAY PER AMM 24-53-01-4 AMM: 24-53-01-5 RAN ENGINES AT IDLE , REMOVED GROUND POWER , APU POWER , RAN A/C ON ALL THREE ENGINE GENERATORS , NO FAULTS , ALL ENGINE GENERATORS PARALLELED CORRECTLY