As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AFTER TAKEOFF RAISED LANDING GEAR TO UP POSITION. ALL LIGHTS (BOTH RED AND GREEN) LANDING GEAR LIGHTS REMAINED ILLUMINATED. FOLLOWED QRH PROCEDURE AND SUCCESSFULLY RETRACTED LANDING GEAR. MAINTENANCE ACCOMPLISHED LANDING GEAR SWING TEST PER FIM 32-30-00-810-815 AND PERFORMED SATISFACTORY OPERATIONAL CHECK.