What was found
RIGHT MAIN GEAR LIGHT DID NOT LIGHT UP UNTIL ALTERNATE EXTENSION GEAR DOOR WAS OPENED. NO WARNING GEAR LIGHT GEAR OPERATED NORMALLY. REMOVED FROM SERVICE. FOUND RH MAIN GEAR GREEN DOWN LOCK LIGHT DIM. ABLE TO DUPLICATE LIGHT OUT WITH MANUAL VIBRATIONS TO LIGHT HOUSING. RELAMPED "RIGHT" MAIN GEAR GREEN DOWN LOCK LIGHTS IAW Q400 AMM 32-31-01-960-801. OPS TEST NORMAL. UNABLE TO DUPLICATE AFTER RELAMP. NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE.