As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) WHEN SELECTING GEAR DOWN FOR ARRIVAL , RECEIVED 3 RED GEAR INDICATION AND NO GEAR EXTENSION. ALTERNATE GEAR EXTENSION USED. AIRCRAFT LANDED NORMALLY. MAINTENANCE REPLACED LANDING GEAR SELECTOR VALVE. GEAR FUNCTION TESTED. AIRCRAFT RETURNED TO SERVICE.