As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NUMBER ONE EHSI RED HDG FLAG AND HDG FAILURE DURING FLIGHT. RETURNED TO PDX. REPLACED NUMBER ONE AHC85 AND INITIALIZATION PROCEDURE WAS PERFORMED. SYSTEM OPS CHECK GOOD. ALL PANELS SECURE. P/N: 622-6190-204, S/N ON: 1121, S/N OFF: 1059.