As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX-ON FLIGHT NUMBER 2335, AFTER GEAR RETRACTION, GREEN NOSE GEAR DOWN INDICATOR REMAINED ILLUMINATED. ALTERNATE GEAR POSITION INDICATOR INDICATED NOSE GEAR WAS RETRACTED. REMOVED AND REPLACED ADVISORY CONTROL UNIT. OPERATIONAL CHECK GOOD AIRCRAFT RETURNED TO SERVICE.