As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) 3 RED GEAR UNSAFE ADVISORY LIGHTS ILLUMINATED WITH LANDING GEAR SELECTED UP AFTER TAKEOFF. THE "ALL LANDING GEAR FAIL TO RETRACT" CHECKLIST WAS CONDUCTED FROM THE QRH WITH NORMAL GEAR DOWN INDICATIONS ON COMPLETION. A RETURN TO LAND. A NORMAL LANDING WAS CONDUCTED WITH NO FURTHER INCIDENCE.