As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER LANDING IN SEA STARTED APU COULD NOT GET APU GENERATOR TO COME ONLINE. GROUNDED - YES. CURRENT FAULTS SHOW 49-41245 AND 49-41254. REMOVED AND REPLACED START CONVERTER UNIT REF B737-900 AMM 49-41-61-000/400-801. CURRENT STATUS SHOWS NO FAULTS. GROUND VERIFICATION PERFORMED CHECKED GOOD REF AMM 49-11-00-860-801.