As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - CREW REPORTED LEFT CONSTANT SPEED DRIVE TEMPERATURE HIGH AND INCREASING ON CLIMBOUT. ACCOMPLISHED QRH PROCEDURES AND DISCONNECTED CSD. AUXILIARY POWER UNIT WOULD NOT START. EMERGENCY DECLARED FLIGHT RETURNED DFW LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT CSD AND GENERATOR. SYSTEM GROUND CHECK NORMAL OPERATION.