As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU AIR STARTER APUC DETECTED LOSS OF AIR TURBINE STARTER FUNCTION. STATUS MSG-3610290 LATCHED TA MODE. REPLACED APU AT SCV & AIR TURBINE STARTER & APU SHUTOFF VALVE, ALL NO HELP. APU STILL DOES NOT START PNEUMATICALLY. REPLACED AIR SUPPLY CABIN PRESSURE CONTROLLER, OPS CKS OK.