As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TAD - FLT 36 - LEFT GEN DRIVE EICAS ILLUMINATED 3 HR INTO FLIGHT LEFT GEN CON DROPPED OFF. INITIATED PROCEDURE IDG DISCONNECTED APU STARTED FINE AT FL410 CONTINUED FLIGHT WITH RIGHT GEN AND APU GEN. REPLACED LEFT GENERATOR CONTROL UNIT SERVICED IDG RAN ENGINE. ELEC OPS NORMAL. (M)