As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) SHORTLY AFTER TAKEOFF THE THRUST REVERSER ISOLATION VALVE CAME ON THE OVERHEAD PANEL. CHECKLIST CAFFIED OUT, A/C RETURNED. LIGHT WENT OUT WHEN THE LANDING GEAR LOWERED. NR 1 THRUST REVERSER HYDRAULIC SYS PRESSURE SWITCH REPLACED.