What was found
AIRCRAFT WAS GROUNDED: DURING TAXI TURNING TO THE RIGHT, #1 ENGINE RUNNING, APU OFF, #2 ENGINE OFF, HAD A COMPLETE LOSS OF ELECTRICAL AND HYDRAULIC POWER. THE AIRCRAFT LOST NOSE WHEEL STEERING AND HAD MINIMAL BRAKING ABILITY. NO ECAM AVAILABLE DUE TO TOTAL LOSS OF ELECTRICAL. FLIGHT CREW STARTED APU. DURING APU START, FLIGHT CREW MOVED THE ENGINE MASTER #1 TO OFF IN CASE OF AN UNKNOWN ENGINE STATUS. THE ENGINE SEEMED TO SHUT DOWN NORMALLY AS ONLY VERIFIED AUDIBLY. (OPEN)