As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO ORD UNDER AMBER ALERT WITH NR 1 ENGINE GENERATOR FAILURE. *S/D* IDG DID NOT DISCONNECT. ROOT CAUSE WAS DUE TO IDG SCAVENGE PUMP/GOVERNOR HOUSING BOLTS COMING LOOSE. THIS ALLOWED VIBRATION WHICH BROKE THE WIRE STRANDS TO THE DISCONNECT SOLENOID. ALSO, LOOSE BOLTS CAUSED IDG PUMP GEAR TO DISENGAGE AND IDG TO LOOSE OIL PRESSURE CAUSING HIGH OIL TEMP PROMPTING CREW TO SHUT DOWN THE ENGINE.