As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 2 HYD ISO VALVE CAUTION LIGHT FLICKERED IN FLIGHT. THE LIGHT ILLUMINATED STEADILY AFTER ATTEMPTED GEAR EXTENSION. GEAR WOULD NOT EXTEND. CREW PERFORMED ALTERNATE GEAR EXTENSION. FOUND NR 2 HYDRAULIC RESRVOIR LOW LEVEL SWITCH INOP. REPLACED SWITCH.