As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU BLEED DUCT LOCATED IN THE AFT ACCESSORY COMPARTMENT RUPTURED ON TAXI OUT. DUCT MATERIAL BROKE ONE OF THE ALTERNATE STAB TRIM CONTROL CABLE PULLEYS CAUSING THE ALTERNATE STAB TRIM CONTROL CABLE TO BIND. REPLACED DUCT, REPAIRED STAB CONTROL SYSTEM.