As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL 340, NR 1 IDG DRIVE LIGHT ILLUMINATED AND VOLTS AND FREQ INDICATED 0. IDG DISCONNECTED VIA CHECKLIST. REPLACED NR 1 ENG IDG IAW NG-800 ASA MM 24-11-400-801 AND 24-11-00-700-802. INSTALLATION TEST AND LEAK CHECK. IS GOOD.