As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA FLIGHT NR 2328: DURING TAXI, ELEVATOR PRESSURE CAUTION ILLUMINATED. AIRCRAFT RETURNED TO GATE. STANDBY HYD PUMP WAS RUNNING WHEN NOT SELECTED. MAINTENANCE FOUND HYD SYS CONT CB H7 PULLED AND COLLARED. REMOVED COLLAR AND RESET CB. PERFORMED OPS TEST OF THE STANDBY POWER UNIT IAW Q400 AMM TASK 29-11-36-710-801. OPS TEST IS GOOD WITH NO DISCREPANCIES NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.