As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SJU INFLIGHT T1416/18MAY - DURING CLIMB, CREW REPORTED LOSS OF LEFT AC BUSS AND LEFT GENERATOR. RETURNED TO SJU AND LANDED WITHOUT INCIDENT. REPLACED LEFT BUSS TIE BREAKER AND GENERATOR CONTROL UNIT. SYSTEM GROUND CHECKED NORMAL OPERATION.