As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - CREW REPORTED AFTER TAKEOFF LEFT ENGINE INTEGRATED DRIVE GENERATOR DROPPED OFF LINE AND WOULD NOT RESET. EMERGENCY DECLARED FLIGHT RETURNED ORD LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT IDG. SYSTEM GROUND CHECK NORMAL OPERATION.