As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AC CROSSTIE LOCKOUT LIGHT ILLUMINATED ON ROTATION WITH NR 1 CSD DISCONNECTED. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. REPLACED AC CROSSTIE RELAY, RIGHT GENERATOR RELAY, AND RIGHT GENERATOR CONTROL PANEL WITH NO HELP. REPLACED LEFT ENGINE GENERATOR CONTROL UNIT. OPERATIONAL CHECK OK. AIRCRAFT RETURNED TO SERVICE.