As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - ON FLIGHT NUMBER 2382, RETURNED TO FIELD, UNEVENTFUL LANDING ACCOMPLISHED. HEADING MISMATCH ANNUNCIATION ON BOTH PFD'D AFTER TAKEOFF, (LEFT SIDE APPEARS CORRECT). TROUBLESHOT NR 2 AHRS SYSTEM TO BAD NR 2 AHRS COMPUTER. REMOVED AND REPLACED AHRS COMPUTER. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.