As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU GEN FAILED DURING PUSHBACK. GROUNDED - YES. REMOVED AND REPLACED APU STARTER GENERATOR IAW AMM 49-41-21. COMPLIED WITH FIM 24-21 TASK 820. FOUND BAD START CONVERTER UNIT. REMOVED AND REPLACED START CONVERTER UNIT AND OPS CHECK GOOD IAW AMM 49-41-61 APU BITE CHECK GOOD IAW AMM 49-61-00-700-801. APU START GENERATOR INSTALLATION TEST GOOD PER AMM 49-41-21-400-801.