As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 909 - MTY-MEX - AIRCRAFT RETURNED TO PLATFORM AS A CONSEQUENCE OF RIGHT ENGINE GENERATOR FAIL. THE APU WAS DEFERRED PREVIOUSLY SO THE GCU AND BCU WERE REPLACED BUT FAIL CHANGE TO LT ENGINE INDICATION. APU TRIM WAS ACCOMPLISHED AND IT WAS OPERATIVE. THE GCU WAS DEFERRED IAW MEL 24-1. DURING TRANSIT CHECK AT CUN STATION, THE GENERATOR WAS REPLACED IAW MM 24-20-07, TEST CORRECT. (M)