As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX FLIGHT NR 2434: AFTER START, NR 3 HYD PUMP CAUTION LIGHT REMAINED ILLUMINATED. MAINTENANCE REMOVED AND REPLACED RL4 RELAY IN THE STANDBY BATTERY CONTACTOR BOX. OPS CHECK GOOD IAW Q400 AMM TASK 29-12-00-720-801. AIRCRAFT RETURNED TO SERVICE.