As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMBOUT, ALL THREE LANDING GEAR RED UNSAFE LIGHTS REMAINED ON AFTER GEAR WAS RETRACTED, RECYCLED GEAR WITH NO HELP. FLIGHT RETURNED TO MSP AND LANDED WITHOUT INCIDENT. REPLACED LANDING GEAR PROXIMITY CONTROL BOX. OPERATIONAL CHECK OK ON GEAR SWING AND AIRCRAFT RETURNED TO SERVICE.