As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, ON GEAR RETRACTION THE NOSE GEAR RETRACTED NORMALLY, BOTH MLG REMAINED GREEN & GEAR DOOR LIGHTS ILLUMINATED RED. WHEN GEAR HANDLE MOVED TO THE GEAR DOWN POSITION ALL 3 GEARS SHOWED DOWN AND GREEN AND THE RED GEAR DOOR LIGHTS WERE EXTINGUISHED. REPLACED NLG PROXIMITY DETECTOR (5GBC) WITH A REPAIRED UNIT IAW MM 32-600. OPS CHECKED GOOD.