As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT 2211, ON CLIMB-OUT FO WAS HAND FLYING THE AIRCRAFT WHEN THE AUTOPILOT ENGAGED AND TURNED TO THE RIGHT. THE FO HIT THE DISENGAGE BUTTON ON THE YOKE AND THE AUTOPILOT DISENGAGED AND FLEW NORMALLY. AFTER THAT, THE FO WAS STARTING A SHALLOW RIGHT TURN WHEN THE AUTOPILOT ENGAGED AND TRIED TO TURN FURTHER TO THE RIGHT. MAINTENANCE REMOVED AND REPLACED THE FLIGHT GUIDANCE COMPUTER AND FGCP. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.