As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE ON FLIGHT 3548 HYDRAULIC GREEN SYSTEM HI TEMP LIGHT ILLUMINATED. AIR RETURN TO MEM. MAINTENANCE REMOVED AND REPLACED GREEN SYSTEM ISOLATION VALVE P/N OFF HTE9531-101, P/N ON HTE9531-3, S/N FRTR010AW. AMM REF 29-36-00-1 RAN ENGINE NR 3 EDP FOR 40 MINUTES, NO GREEN SYSTEM LIGHT. LEAK CHECK AND NO LEAKS.