What was found
CREW REPORTED, AFTER NUMEROUS ATTEMPTS TO LOWER THE GEAR, DID NOT RECEIVE 3 GREEN LIGHTS. AN ALTERNATE EXTENSION WAS PERFORMED AND AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED BOTH MAIN LANDING GEAR DOWNLOCK SWITCHES, AND INSTALLED A NEW CONTROLLER. OPERATIONAL CHECKS WERE GOOD. PROBLEM HAD REOCCURRED DURING TEST FLIGHT. MAINTENANCE REPLACED THE RIGHT MAIN LANDING GEAR DOWNLOCK ACTUATOR. TEST FLIGHT WAS SATISFACTORY. AIRCRAFT WAS RETURNED TO SERVICE.