As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT DECK EXPERIENCED A MOMENTARY ELECTRICAL POWER FAILURE. AUTO-PILOT DROPPED-OFF, POWER SELF RESTORED WITH NO EICAS MESSAGES. PASSENGER CABIN EXPERIENCED NO ELECTRICAL POWER LOSS. *S/D* BUS POWER CONTROL UNIT WAS REPLACED. NO FURTHER DISCREPANCY HAS OCCURRED.