As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE N AMBER CAS: SHOPRTLY AFTER PLACING THE GEAR HANDLE IN THE UP POSITION WE RECEIVED AN AMBER "GEAR DISAGREE N" AND AN AMBER "ADC SSEC MISCOMPARE" CAS MESSAGES. CHECKLIST WAS REFERENCED AND COMPLETED. NOSE GEAR NEVER MOVED FROM THE DOWN AND LOCKED POSITION. NO ABNORMAL NOISES OR THUMPING OCCURRED. MAIN HEAR LOWERED NORMALLY. CORRECTIVE ACTION: REPLACED LANDING GEAR HANDLE. OPS CHECK GOOD. IAW 680A AMM 32-30-30.