As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE APU FAILED TO START AFTER LANDING, INDICATING A FAULT ON THE CONTROL PANEL. TROUBLESHOOTING IDENTIFIED THAT THE STARTER GEN DRIVE ADAPTER PN 3861055-1 FAILED. THE BROKEN DRIVE ADAPTER WAS REMOVED & A NEW ADAPTER INSTALLED.