As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT AT FL450 AIRCRAFT LOST POWER ON EICAS DISPLAY UNITS, 1 ,2, AND 3 CAUSED DUE TO A POWER LOSS ON THE NR 1 POWER BUSS. THE LOSS OF ONE THE NR 1 BUSS WAS CAUSED BY A FAILED GENERATOR CONTROL UNIT. THE LOSS OF POWER ON THE NUMBER ONE BUS ALSO CAUSED THE AUTOPILOT TO DISENGAGE AND THE LOSS OF POWER TO THE DIGITAL PRESSURIZATION CONTROLLER.