As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - DEICE PRESSURE CAUTION LIGHT ILLUMINATED. RUNNING THE CHECKLIST, NOTICED THE LEFT OUTBOARD BOOT LIGHT DIDN'T ILLUMINATE. THE DEICE PRESSURE IS NORMAL THROUGH ALL CYCLES. MAINTENANCE REMOVED AND REPLACED THE NR 5 DDV. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.