As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 4265 - AFTER TAKEOFF THE LEFT GENERATOR FAILED. AN OPERATIONAL DECISION WAS MADE TO RETURN TO BOS. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED LEFT GCU. SYSTEM CHECKED GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (M)