As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT DIRECTOR FAILED TURNING FINAL IN PORTLAND AROUND 2000FT MSL. COULD NOT ESTABLISH THE FLIGHT DIRECTORS FOR THE REMAINDER OF FLIGHT. GROUNDED - YES. PERFORMED DFCS BITE IAW B737-800 FIM 22-11 TASK 801. NO FAULTS FOUND. PERFOMRED OPS TEST IAW 22-11 TASK 801 FOR CURRENT STATUS AND GROUP 12 FOR FLIGHT DIRECTOR TEST. OPS TEST GOOD. NO DEFECTS NOTED. SYSTEM WORKS NORMALLY.