As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE-OFF AND GEAR UP SELECTION THE RED GEAR UNSAFE LIGHT REMAINED ILLUMINATED. THE CREW CYCLED THE GEAR WITH THE SAME RESULT. THEY RETURNED TO THE DEPARTURE AIRPORT AND ON GEAR DOWN SELECTION HAD THREE GREEN INDICATED WITH NO RED UNSAFE LIGHT. THEY LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE JACKED THE AIRCRAFT AND CYCLE THE LANDING GEAR AND FOUND NO ANOMALIES. THEY CLEANED AND TESTED THE GEAR UPLOCK SWITCHED AND NO FAULTS WERE FOUND.