As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO BLOCKS: FLIGHT NR 8800, ON TAXI TO RUNWAY IN GEG STANDBY ELECTRIC GENERATOR FAULT LIGHT ILLUMINATED. ATTEMPTED RESET WAS UNABLE TO CLEAR THE FAULT, PILOT ELECTED TO RETURN TO RAMP. MAINTENANCE REMOVED AND REPLACED THE ALTERNATOR CONTROL UNIT. (K)