As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX FLIGHT NR 2149 - DURING TAXI, THE FIRST OFFICER'S EADI SHOWED ON 8 DEGREE PITCH DOWN WITH 10-15 DEGREES BACK. NO MESSAGES WERE DISPLAYED ON THE EADI OR ADVISORY PANEL. REINITIALIZED NR 2 AHRS, FIRST OFFICER'S ADI POWER UP SELF TEST NORMAL. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.