As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MLG LANDING GEAR EXTENSION: ALL THREE LANDING GEAR FAILED TO EXTEND WITH GEAR HANDLE IN DOWN POSITION. AMBER "GEAR DISAGREEMENT L R N" CAS MESSAGE ILLUMINATED. CORRECTIVE ACTION: REPLACED LANDING GEAR CONTROL MANIFOLD. OPS CHECK GOOD. IAW CE680A MM 32-30-20.