As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR POSITION & WARNING: AFTER TAKEOFF GEAR HANDLE SELECTED UP. GEAR REMAINED IN DOWN POSTION AND A YELLOW CAS GEAR DISAGREE DISPLAYED. ALSO GEAR INDICATIONS WERE DN IN YELLOW. PERFORNED REQUIRED QRH CHECKLIST AND RETURNED FOR LANDING. // SIGNOFF// REMOVED LANDING GEAR CONTROL MODULE PN 9912750-2 SN 00761 INSTALLED OVERHALED LANDING GEAR CONTROL HANDLE MODULE PN 9912750-2 SN 00653 IN ACCORDANCE WITH 680A MM 32-30-30 LANDING GEAR OPERATIONAL CHECKS GOOD IN ACCORDANCE WITH 680A MM 32-00-00