As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU DID NOT START REF L/P 60180243. GROUNDED - YES. ACCOMPLISHED FIM TASK 49-46 TASK 803 REMOVED AND REPLACED STARTER GENERATOR REF B737-900 AMM 49-41-21OPS CHECKS GOOD PULLED AND 3C/B REMOVED COLLER AND CLOSED 3 C/B. WHILE T/S FOUND MOISTURE IN START POWER UNIT REPLACED PER AMM 49-41-71-401 OPS TEST PASSED.