As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER SHUTDOWN, NR 1 ENGINE CONTINUED TO WINDMILL WITH APU BLEED AIR PRESSURE. SWITCHED APU BLEED AIR SWITCH FROM OFF TO ON AND BLEED SOURCE WAS REMOVED FROM ENGINE. REMOVED AND REPLACED HIGH STAGE VALVE IAW AMM 36-11-85. OPS AND LEAK CHECKED OK.