As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
POWER DROPPED OFFLINE PRIOR TO PUSHBACK. FLAGGED SDR FOR LOSS OF ELEC POWER REPLACED APU GENERATOR CONTROL UNIT REF AMM TASK 24-22-02-400-801. TESTS ARE OK REF AMM TASK 24-22-02-710-802. VERIFIED RIGHT BUS MAINTAINS POWER ON APU GENERATOR AND EXTERNAL POWER.