As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT THE LT GEN FAILED IN FLIGHT & THEY WERE UNABLE TO RESET THE GEN IAW THE ACFT CHECKLIST. TROUBLESHOOTING IDENTIFIED THE LT GCU AS DEFECTIVE, PN 51539-006J, SN Y1434. THE DEFECTIVE GCU WAS REMOVED & AN OVERHAULED GCU WAS INSTALLED. OPERATIONS CHECKED SATISFACTORY & THE AIRCRAFT WAS RETURNED TO SERVICE.