As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - MAIN BRAKES COMPLETELY FAILED WHILE AIRCRAFT WAS AT A COMPLETE STOP ON THE TAXI WAY. USED ALTERNATE BRAKES TO STOP AIRCRAFT FROM ROLLING. DURING TAXI BACK TO THE GATE MAIN BRAKES CAME BACK. MAINTENANCE INSPECTED SYSTEM AND FOUND NO DEFECTS. PLACED ANTI-SKID SYSTEM ON MEL. MEL CLEARED BY REINSPECT OF ANTI-SKID SYSTEM, NO FAULT FOUND. NO PARTS REPLACED.