As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - FLIGHT 4430 - NR 2 GENERATOR FAIL MESSAGE (CONSTANT SPEEDDRIVE INOP). RETURNED TO THE GATE. MAINTENANCE PLACED THE SYSTEM ON MEL. AIRCRAFT RETURNED TO SERVICE. NR 2 IDG REPLACED. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.