As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ALL LANDING GEAR LIGHT STAYED RED AFTER GEAR EXTENSION. LIGHTS WERE TESTED AND NONE ILLUMINATED RED. RETRACTION AND EXTENTION WERE COMPLETED AGAIN. AFTER 5 MINUTES ALL LIGHTS GREEN APPEARED. *S/D* REPLACED PROXIMITY ELECTRONIC UNIT U1-126 AND OPERATIONALLY CHECKED THE LANDING GEAR WARNING SYSTEM.