What was found
(CAN) DURING A MISSED APPROACH PILOT INITIATED A TURN TO RETURN FOR A 2ND APPROACH WHEN MLG EXTENDED UNCOMMANDED WITH NO DOWN OR UP INDICATION LIGHTS. PILOT SLOWED ACRFT & CONTINUED TO DESTINATION WITH MLG SELECTED DOWN & CONFIRMED MLG DOWN WITH EMERGENCY GEAR HANDCRANK. MX INSPECTED ACRFT & FOUND MLG DYNAMIC BRAKING RELAY TO BE MALFUNCTIONING. ON INSPECTION OF RELAY, DETERMINED THAT A SPRING OFF OF ONE OF THE CONTACTS HAD BROKEN IN HALF & BROKEN PIECE HAD SHORTED OUT RELAY CAUSING MLG TO EXTEND. RELAY REPLACED & ACRFT TEST FLOWN WITH NO REOCCURANCE. INSTALLATION DATE OF THE RELAY COULD NOT BE FOUND BUT MANUFACTURING DATE 6/77.