As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF AND SELECTED GEAR HANDLE UP, 3 GREEN LIGHTS REMAINED ILLUMINATED ALONG WITH 3 RED GEAR UNSAFE LIGHTS. GEAR DID NOT RETRACT. CYCLED LANDING GEAR SELECTOR PER CHECKLIST AND SAME SCENARIO OCCURRED FOR 15 SECONDS. GEAR RETRACTED AND INDICATION RETURNED TO NORMAL WITH NO CAUTION LIGHTS. HYDRAULIC PRESSURE AND QUANTITIES NORMAL. REMOVED AND REPLACED PROXIMITY SENSOR. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.