As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT DECLARED EMERGENCY ON ACCOUNT OF CENTER HYDRAULIC PRESSURE AND QUANTITY LOSS. MAINTENANCE REPORTS UPON TROUBLE SHOOTING FOUND SYSTEM DEPLETED DUE TO ADP MODULE DPI SWITCH LAKING, REPLACED ADP DPI, SERVICED OPS CHECK AND LEAK CHECK GOOD. PRESSURE NORMAL IAW AMM 29-11-19.