As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON GEAR EXTENSION 3 RED AND HANDLE WARNING LIGHTS ILLUMINATED, GEAR DID NOT EXTEND. PERFORMED GEAR EXTENSION 3 GREEN DOWN AND LOCKED. JACKED ACFT, SWUNG GEAR SEVERAL TIMES, FOUND LANDING GEAR SELECTOR VALVE AT FAULT. REMOVED AND REPLACED LANDING GEAR SELECTOR VALVE IAW 32-40-41. SWUNG GEAR SEVERAL TIMES, OPS CHECKED GOOD. OK FOR RETURN TO SERVICE