What was found
RETRACTION OF GEAR (R) GEAR DOOR REMAINED OPEN (LIGHT ILLUMINATED). RECYCLED GEAR (2X)-GEAR DOWN. RIGHT MAIN WOULD NOT COME DOWN (NO GREEN)-GEAR UP, DOOR STAYED OPENED (AMBER LIGHT ON). ALTERNATE GEAR EXTENSION CONDUCTED SUCCESSFULLY. (MX) FOUND AND CLEANED CORROSION ON RIGHT MLG PROX SENSOR CONNECTORS IAW DHC-8-400 MM, 32-31-41. COULD NOT DUPLICATE DISCREPANCY. SWAPPED MLG SOLENOID CONTROL VALVES IAW DHC-8-400 MM, 32-61-06. POST MAINTENANCE CHECK FLIGHT GOOD.