As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED LEFT ENGINE GENERATOR FAILED AND AUXILIARY POWER UNIT WOULD NOT START AFTER THREE ATTEMPTS. FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT ENGINE CONSTANT SPEED DRIVE GENERATOR. SYSTEM GROUND CHECK NORMAL OPERATION.